Patent Grant
12040564
The present disclosure is directed to a reconfigurable patch antenna, and more particularly relates to a frequency and pattern reconfigurable segmented patch antenna for WiMAX applications.
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.
WiMAX, also known as worldwide interoperability for microwave access, is a broadband wireless technology that is effective for providing wireless data transmission over long distances in a variety of ways, for example, from point-to-point link to full mobile cellular type access. WiMAX can provide high-speed data communication with an ability to maintain dedicated links, broadband connectivity and VoIP services. WiMAX is based on a broadband wireless access standard set by the Institute of Electrical and Electronics Engineers (IEEE 802.16) that acts as an alternative to cable and DSL. WiMAX is increasingly appearing as a promising option of wireless replacement for wired broadband. Range is important factor for WiMAX technology because a single WiMAX tower can connect to other WiMAX towers through a line-of-sight microwave link.
Patch antennas have the capability to reconfigure frequency bands and radiation patterns and have attracted interest for wireless applications. Patch antennas are useful for operating in more than one frequency band. In a patch antenna, frequency reconfigurability is achieved by varying the length of the antenna using a PIN diode. Also, radiation pattern reconfigurability is achieved with a use of parasitic elements.
Patch antennas for frequency and radiation pattern reconfigurability have been reported in the literature. For example, a rhombus-shaped patch radiator with integrated 6 PIN diodes was shown to provide 5.2 GHz and 8.8 GHz at two different radiating patterns, i.e., −45°/45° at 2 modes with 2 bands [see Y. P. Selvam, L. Elumalai, M. G. N. Alsath, M. Kanagasabai, S. Subbaraj, and S. Kingsly, “Novel frequency- and pattern-reconfigurable rhombic patch antenna with switchable polarization,” IEEE Antennas and Wireless Propagation Letters, vol. 16, pp. 1639-1642, 2017]. Here, the mode refers to the direction the antenna could direct its beam or radiation pattern. In another example, a patch antenna includes 5 PIN diodes placed to realize two frequency bands operating at 2.4 and 5.4 GHz at two different beam patterns, i.e., 2 modes with 2 bands [see P. K. Li, Z. H. Shao, Q. Wang, and Y. J. Cheng, “Frequency- and pattern reconfigurable antenna for multistandard wireless applications,” IEEE Antennas and Wireless Propagation Letters, vol. 14, pp. 333-336, 2015]. In another example, a patch antenna includes 8 PIN diodes loaded on a radiating patch to achieve 1.9 and 2.4 GHz resonance, with 2 omnidirectional switching beams at each resonance frequency, i.e., 4 modes with 2 bands, wherein the frequency and pattern reconfigurability is achieved by two shorting screws placed symmetrically and asymmetrically to modify the radiating elements [see S. Y. Z. Zhu, P. Wang and P. Gao, “A flexible frequency and pattern reconfigurable antenna for wireless systems,” Progress In Electromagnetics Research Letters, vol. 76, pp. 63-70, 2018]. Other patch antenna configurations have been reported in the art. For example, a microstrip patch antenna with 2 varactor diodes achieves 3 resonant frequency bands from 2.68-3.51 GHz with a broadside and monopole-like radiation patterns, that is, 2 modes with 3 bands. [see N. Nguyen-Trong, L. Hall, and C. Fumeaux, “A frequency- and pattern re configurable center-shorted microstrip antenna,” IEEE Antennas and Wireless Propagation Letters, vol. 15, pp. 1955-1958, 2016]. In another example, the removal of two slits from a rectangular patch antenna has been reported in the art that couples with 4 PIN diodes. The antenna permits 4 operating frequencies at 4.5, 4.8, 5.2, 5.8 GHz, and 3 different radiation pattern, i.e., 3 modes with 4 bands. [see Y. P. Selvam, M. Kanagasabai, M. G. N. Alsath, S. Velan, S. Kingsly, S. Subbaraj, Y. V. Ramana Rao, R. Srinivasan, A. K. Varadhan, and M. Karuppiah, “A low-profile frequency- and pattern-reconfigurable antenna,” IEEE Antennas and Wireless Propagation Letters, vol. 16, pp. 3047-3050, 2017.] In another example, a patch antenna provides 6 different radiation patterns at frequency bands of 2.6 GHz and 3.5 GHz by using 6 pin diodes over an aperture-coupled stacked microstrip array antenna. The antenna provides 6 mode with 2 bands. Frequency and radiation pattern reconfigurability was achieved by changing the lengths of the feedline and radiating elements. [see N. Ramli, M. T. Ali, M. T. Islam, A. L. Yusof, and S. Muhamud-Kayat, “Aperture-coupled frequency and patterns reconfigurable microstrip stacked array antenna,” IEEE Transactions on Antennas and Propagation, vol. 63, no. 3, pp. 1067-1074, March 2015]. In another example, 2 varactor diodes are integrated with loaded stubs on 2 patch antenna array antennas has also been disclosed in the art. By changing the bias voltages of the varactor diodes, 3 tuning range of 2.15, 2.27, 2.38 GHz and also 3 radiation pattern angles at each tuning frequency were achieved, thus making the antenna work in 9 different modes with 3 frequency band. [see S. N. M. Zainarry, N. Nguyen-Trong, and C. Fumeaux, “A frequency and pattern-reconfigurable two-element array antenna,” IEEE Antennas and Wireless Propagation Letters, vol. 17, no. 4, pp. 617-620, April 2018].
Each of the aforementioned antennas suffer from one or more drawbacks hindering their adoption. For example, aforementioned patch antennas designs could achieve up to 9 operational modes with 3 frequency bands with the help of 2 switches having small or no differences in the resonance frequencies, thus making the frequencies not completely independent and less operationally useful. Also, some designs in which high frequency reconfigurability is achieved, that is, more number of supported frequency bands, the number of modes supported by the antenna are less, thus limiting the radiation pattern of the antenna. Also, most conventional patch antennas include a high number of switches to achieve high frequency reconfigurability which in turn impacts the cost of the antenna. Conventional patch antennas are large and when configured to smaller size provide 7 or less operational modes. If the number of switches is increased to achieve high frequency reconfigurability, the antenna may fail to provide a greater number of radiation patterns or modes of operation.
Therefore, it is an object of the present disclosure to provide a highly compact patch antenna design that is capable of providing high frequency reconfigurability, that is, more resonating bands along with high number of operational modes and corresponding radiation patterns, with a decreased number of switches that is useful in WiMax applications in multipath environment.
In an exemplary embodiment, a frequency and pattern reconfigurable segmented patch antenna for WiMAX applications is described herein. The segmented patch antenna includes two rectangular parasitic elements. Each parasitic element comprises an integrated diode. The segmented patch antenna includes a main rectangular patch segment. The main rectangular patch segment includes 3 slots, 2 slits and 3 diodes. The segmented patch antenna is suitable for use in multiple frequencies between 4.1 GHz and 5.7 GHz inclusive and configurable to operate in 12 independent modes.
In another exemplary embodiment, the segmented patch antenna further includes 4 biasing lines having length and width of each biasing line between 7 and 8 mm and between 1 and 3 mm, respectively.
In another exemplary embodiment, each of the 4 biasing lines further include a limiting resistor and a choke inductor.
In another exemplary embodiment, the main rectangular patch segment has one edge of length between 26 and 28 mm and a second edge of length between 21 and 23 mm.
In another exemplary embodiment, the slots are of width 0.6 mm (±0.1 mm). and the slits are no larger than 0.1 (±0.01) mm.
In another exemplary embodiment, each of the two rectangular parasitic elements have one dimension between 26 and 28 mm and another dimension between 2.5 and 3.5 mm.
In another exemplary embodiment, the rectangular parasitic elements are located at one quarter wavelength from the center on each side of the main patch segment wherein an average of quarter wavelengths of each frequency is used to calculate the location of the parasitic elements.
In another exemplary embodiment, the rectangular parasitic elements are located between 18 and 19 mm from the center of the main rectangular patch segment.
In another exemplary embodiment, each of the two rectangular parasitic elements are separated into two sections by pin diodes D1 and D2.
In another exemplary embodiment, a length of the rectangular parasitic elements is configurable by turning on or off the diodes.
In another exemplary embodiment, the parasitic elements are reconfigurable to act as a reflector or as a director according to the settings of the diodes and the Yagi-Uda principle. [see Y. Mushiake, “A theoretical analysis of the multi-element end-fire array with particular reference to the yagi-uda antenna,” IRE Transactions on Antennas and Propagation, vol. 4, no. 3, pp. 441-444, July 1956 for more details of the Yagi-Uda principle]
In another exemplary embodiment, three pin diodes D3, D4 and D5 are integrated on the 3 slots of the main rectangular patch segment in order to vary the length of the main rectangular patch thereby varying the length of the resonance frequency of the segmented patch antenna.
In another exemplary embodiment, the segmented patch antenna supports at least 4 frequency bands.
In another exemplary embodiment, the segmented patch antenna is reconfigurable to 12 independent modes.
In another exemplary embodiment, the segmented patch antenna has efficiency of at least 92% while configured to transmit at 5 GHz.
In another exemplary embodiment, the segmented patch antenna operates with average gain of 3 dBi throughout the 12 independent modes.
In another exemplary embodiment, the segmented patch antenna operates with average efficiency of 77%, throughout the 12 independent modes.
In another exemplary embodiment, a back view of the segmented patch antenna includes a partial ground with one dimension between 2.5 and 3.5 mm and a second dimension between 22 and 25 mm.
In another exemplary embodiment, the back view of the segmented patch antenna further includes a coaxial feed that is placed between 10 and 12 mm from a top of the partial ground.
In another exemplary embodiment, the area of the segmented patch antenna is less than 55×55 mm2.
The foregoing general description of the illustrative embodiments and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive.
A more complete appreciation of this disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
In the drawings, like reference numerals designate identical or corresponding parts throughout the several views. Further, as used herein, the words “a,” “an” and the like generally carry a meaning of “one or more,” unless stated otherwise.
Furthermore, the terms “approximately,” “approximate,” “about,” and similar terms generally refer to ranges that include the identified value within a margin of 20%, 10%, or preferably 5%, and any values therebetween.
Aspects of this disclosure are directed to a frequency and pattern reconfigurable segmented patch antenna (SPA) for WiMAX Applications. The SPA has a compact and conformal antenna design, employing 5 switches that permit 12 operational modes with better bandwidth, average gain, and efficiency of 3 dBi and 77%, respectively, throughout the twelve operational modes. The SPA includes a radiating patch with three incorporated slots and two slits. Three PIN diodes are integrated on the three slots to vary a length of the radiating patch to permit frequency reconfiguration at 4.1 GHz, 4.7 GHZ, 5.0 GHz, and 5.7 GHZ, preferably ±0.1 GHz or ±0.5 GHZ, that is, four frequency bands. The two slits are also incorporated in order to independently bias the three diodes. Two parasitic elements are configured to act as either a reflector or a director, each placed at a quarter wavelength based upon an average of quarter wavelengths of each frequency that the SPA 100 may be configured according to the Yagi-Uda principle. The SPA exhibits large number of switchable modes at four resonance frequency bands with relatively large gain and efficiency throughout all the modes, making the disclosed antenna an excellent candidate for WiMAX applications.
Accordingly, embodiments of the present disclosure relate to a frequency and pattern reconfigurable segmented patch antenna (SPA) 100 for WiMAX Applications. As shown in
The front side 100F and the back side 100B are separated by a substrate 100S over which the components of the SPA 100 are integrated. In an embodiment, the substrate 100S is made up of a dielectric material. The dielectric material may be selected from a group containing an FR-4 PCB, a PTFE material, Rogers RO4350 or Rogers RT5880 substrate and such substrates. In some examples, the substrate 100S is selected as Rogers RT5880 of dielectric constant value 2.2+/−0.2, preferrable +/−0.1 and loss tangent 0.0009 and height 1.572 mm. The selection of the dielectric material is not limited to the group, and any other known material may be selected to act as a base material for designing an electronic circuit of the SPA 100. Also, length and width of the substrate 100S is W8 unit along Y axis and W7 unit along X axis, respectively. In some examples, W7=W8=50 mm or less (±5 mm, preferably ±2 mm). Accordingly, the total volume of the SPA 100 is 50 mm (±5 mm, preferably ±2 mm)×50 mm (±5 mm, preferably ±2 mm)×1.572 (±0.1 mm, preferably ±0.05 mm) or less than or equal to 55×55×1.672 mm3 in volume.
The front side 100F of the SPA 100 includes two rectangular parasitic elements 102, that is, the first rectangular parasitic element 102-1 and the second rectangular parasitic element 102-2. The rectangular parasitic element 102 refers to a conductive sheet, such as an etched metallic sheet disposed over the substrate 100S located at the front side 100F of the SPA 100. The length and the width of each of the rectangular parasitic element 102, that is, the first rectangular parasitic element 102-1 and the second rectangular parasitic element 102-2, is W4 unit along X axis and W5 unit along Y axis. In an example, a length of the rectangular parasitic element 102, that is, W4 is 26.7 mm or can be between 26 mm and 28 mm. Also, as an example, the width of the rectangular parasitic element 102, can be, W5=3.2 mm (±0.4 mm). Also, the first rectangular parasitic element 102-1 is located at W9 units from the third edge E3 and W10 units from the first edge E1. Similarly, the second rectangular parasitic elements 102-2 is also located at a distance of W9 units from the fourth edge E4 and W10 units from the first edge E1. In an example, W9 is equal to 7.4 mm (±0.7 mm) and W10 is equal to 15.65 mm (±1.5 mm).
The first rectangular parasitic element 102-1 is separated into two sections, that is, a first section 102-1-1 and a second section 102-1-2. Each section has a length equal to W4/2 units along X axis. In order to create the section on each rectangular parasitic element 102, the disposed first rectangular parasitic element The pair of parasitic elements are etched out, through any known metal etching process such as a chemical or wet etching process, at a distance W10±W4/2 units from the first edge E1, in the X axis direction. Etching out the metallic sheet divides the first rectangular parasitic elements 102-1 into two equal parts. The parts are thus, for example, referred to as the first section 102-1-1 and the second section 102-1-2, respectively. The first diode 104 is electrically connected to the first section 102-1-1 and the second section 102-1-2. For example, a first terminal (not shown) of the first diode 104 is connected (e.g., soldered) to the first section 102-1-1, and a second terminal (not shown) of the first diode 104 is soldered to the second section 102-1-2. The electrical arrangement therefore establishes an electrical connection between the first section 102-1-1 and the second section 102-1-2 through the first diode 104. The electrical connection so established is utilized to either increase or decrease the length of the first rectangular parasitic elements 102-1. Accordingly, the length of the first rectangular parasitic elements 102-1 is configurable by turning on or off the first diode 104. Based upon a bias setting of the first diode 104, that is, turning on or off the first diode 104, as well as based upon the Yagi-Uda principle, the first rectangular parasitic element 102-1 is reconfigurable to either function as a reflector or a director of the SPA 100.
The second rectangular parasitic elements 102-2 is also separated into two sections, that is, a third section 102-2-1 and a fourth section 102-2-2. Each section has a length equal to W4/2 units along the X axis. Through the etching process, the second rectangular parasitic elements 102-2 is divided into two equal parts. The parts are thus referred to as the third section 102-2-1 and the fourth section 102-2-2, respectively. Also, a second diode 106 is electrically connected to the third section 102-2-1 and the fourth section 102-2-2. For example, a first terminal (not shown) of the second diode 106 is soldered to the third section 102-2-1, and a second terminal (not shown) of the second diode 106 is soldered to the second section 102-2-2. The electrical arrangement therefore establishes an electrical connection in between the third section 102-2-1 and the fourth section 102-2-2 through the second diode 106. The electrical connection so established is utilized to either decrease or increase a length of the second rectangular parasitic elements 102-2. Accordingly, the length of the second rectangular parasitic elements 102-2 is configurable by turning on or off the second diode 106. Therefore, based upon a bias setting of the second diode 106, that is, turning on or off the second diode 106, as well as based upon the Yagi-Uda principle the second rectangular parasitic element 102-1 is also reconfigurable to either function as a director or a reflector of the SPA 100.
The front side 100F of the SPA 100 includes the main rectangular patch segment 108. The main rectangular patch segment 108 refers to another conductive sheet, such as a metallic sheet disposed over the substrate 100S located at the front side 100F of the SPA 100. The length and the width of the main rectangular patch segment 108 W1 unit along the Y axis and W2 unit along the Y axis. In an example, the length of the main rectangular patch segment 108, that is, W1=26.9 mm (±1 mm) Also, as an example, the width of the main rectangular patch segment 108, that is, is W2=22.1 mm (±2 mm) Also, the main rectangular patch segment 108 is located at a distance of W12 units from the first edge E1. In an example, W12 is equal to 17.95 (±1.8 mm).
The main rectangular patch segment 108 includes at least three slots, that is, the first slot 110, the second slot 112 and the third slot 114. In order to create the first slot 110 on the main rectangular patch segment 108, the disposed main rectangular patch segment 108 is etched out, through any known metal etching process such as a chemical or wet etching process, at a distance of W13 unit from the first edge E1, along the X axis till the distance of W1/2 unit. Etching out the main rectangular patch segment 108 therefore creates the first slot 110 of length W1/2 units at a distance of W9+W5+W11 unit from the third edge E3 along the Y-axis, and W13 units from the first edge E1 along the X-axis direction. Similarly, in order to create the second slot 112 on the main rectangular patch segment 108, the disposed main rectangular patch segment 108 is etched out at a distance of W13 unit from the first edge E1, along the X-axis till the distance of W1/2 unit, opposite to the first slot 110. Etching out the main rectangular patch segment 108 therefore creates the second slot 112 of length W1/2 units at a distance of W9+W5+W11 unit from the fourth edge E4 along the Y-axis and W13 units from the first edge E1 along the X-axis. Accordingly, the first slot 110 and the second slot 112 appear as a continuation of a slot of length W1 unit at a distance of W13 units from the first edge along the Y-axis direction. The first slot 110 and the second slot 112 have a distance of W1/2 units each. In order to create the third slot 114 on the main rectangular patch segment 108, the disposed main rectangular patch segment 108 is etched out vertically in a downward direction at a distance of W12 units from the first edge E1 and at a mid-point of the main rectangular patch segment 108. Etching out the main rectangular patch segment 108 creates the third slot 114 of length W2-W3 units at a distance of W12 units from the first edge E1 in vertically downward direction towards the X-axis. Accordingly, the third slot 114 touches the first slot 110 and the second slot 112. The first slot 110, the second slot 112 and the third slot 114 have a width between 0.5 mm and 0.7 mm. In an embodiment, each slot has a width equal to 0.6 mm (±0.1 mm) Creating of the first slot 110 and the third slot 114 cuts the main rectangular patch segment 108 into a first part 108-1. Similarly, creation of the second slot 112 and the third slot 114 cuts the main rectangular patch segment 108 into a second part 108-2.
The main rectangular patch segment 108 further includes at least two slits, for example the first slit 116 and the second slit 118. In order to create the first slit 116 on the main rectangular patch segment 108, the disposed main rectangular patch segment 108 is etched out at a distance of W13 unit from the first edge E1, and the first slit 116 is located in vertical direction at a distance of W9+W5+W11+W14 units from the third edge E3. Etching out the main rectangular patch segment 108 therefore creates the first slit 116 of length W3 units at a distance of W9+W5+W11+W14 units from the third edge E3 and W13 units from the first edge E1. Similarly, in order to create the second slit 118 on the main rectangular patch segment 108, the disposed main rectangular patch segment 108 is etched out at a distance of W13 unit from the first edge E1, and the second slit 118 is located in a vertical direction at a distance of W9+W5+W11+W15 units from the fourth edge E4. Etching out the main rectangular patch segment 108 creates the second slit 118 of length W3 units at a distance of W9+W5+W11+W15 units from the fourth edge E4 and W13 units from the first edge E1. Also, the first slit 116 touches and is perpendicular to the first slot 110 and the second slit 118 touches and is perpendicular to the second slot 112. In an embodiment, the first slit 116 and the second slit 118 has a thickness no larger than 0.1 mm (±0.01 mm). Therefore, there is almost no effect of the slits on the resonance frequency of the SPA 100, since 0.1 mm (±0.01 mm) is a smallest possible value required for fabrication. Creating the first slit 116 with the first slot 110 divides the main rectangular patch segment 108 into a third part 108-3. Similarly, creating of the second slit 118 with the second slot 112 cuts the main rectangular patch segment 108 into a fourth part 108-4. Also, an area of the main rectangular patch segment 108 illustrated in between the first slit 116 and the second slit 118 represents a fifth part 108-5 of the main rectangular patch segment 108. Accordingly, the combination of three slots and two slits over the main rectangular patch segment 108 cuts the main rectangular patch segment 108 into five parts.
The main rectangular patch segment 108 includes at least three diodes, that is, the third diode 120, the fourth diode 122 and the fifth diode 124. The third diode 120 is electrically connected to the first part 108-1 and the third part 108-3. For example, a first terminal (not shown) of the third diode 120 is soldered to the first part 108-1 and a second terminal (not shown) of the third diode 120 is soldered to the third part 108-3. Similarly, the fourth diode 122 is electrically connected to the second part 108-2 and the fourth part 108-4. For example, a first terminal (not shown) of the fourth diode 122 is soldered to the second part 108-2 and a second terminal (not shown) of the fourth diode 122 is soldered to the fourth part 108-4. Also, the fifth diode 124 is electrically connected in between the first part 108-1 and the second part 108-2. For example, a first terminal (not shown) of the fifth diode 124 is soldered to the first part 108-1 and a second terminal (not shown) of the fifth diode 124 is soldered to the second part 108-2. Accordingly, three diode arrangements establish an electrical connection in between the first part 108-1, the second part 108-2, the third part 108-3 and the fourth part 108-4. The electrical connection established is utilized to either increase or decrease or vary a length of main rectangular patch segment 108. Accordingly, the main rectangular patch segment 108 is viewed as a segmented patch as a result of the first slot 110, the second slot 112 and the third slot 114. Also, due to the presence of two slits: the first slit 116 and the second slit 118, the third diode 120 and the fourth diode 122 can be biased independently and also avoid any physical connection. Accordingly, the length of the main rectangular patch segment 108 is configurable by turning on or off the three diodes. As such, the three diodes integrated on the three slots of the main rectangular patch segment 108 are configured to vary the length of the main rectangular patch segment 108. Varying the length of the main rectangular patch segment 108 therefore varies the length and consequently the resonance frequency of the SPA 100. Therefore, based on bias settings of the each of the three diodes, that is, turning on or off, the length of the main rectangular patch segment 108 is also reconfigurable.
The main rectangular patch segment 108 further includes a feed point 134 over the fifth part 108-5 of the main rectangular patch segment 108. The feed point 134 is located at a mid-location of the main rectangular patch segment 108, that is, at a distance of W9+W5+W11+W1/2 from the third edge E3. In another example, an imaginary axis 136 may be considered that bisects the main rectangular patch segment 108 into two equal parts. Each part, thus formed, has length of W1/2 units. The feed point 134 may be located at the bisecting location, that is, over the imaginary axis 136. In some examples, the position of the feed point 134 may be anywhere over the imaginary axis 136 within the fifth part 108-5. One terminal of the feed point 134 may be soldered over the fifth part 108-5 of the main rectangular patch segment 108. Another terminal of the feed point 134 is electrically connected to the back side 100B of the SPA 100 that electrically couples a partial ground (not shown here) located at the back side 100B of the SPA 100. For example, a hole (not shown) may be created over the fifth part 108-5 as well as over the substrate 100S immediately below the hole of the fifth part 108-5. The hole (not shown) thus acts as a via (not shown) that opens at the back side 100B of the SPA 100. At the back side 100B, the via (not shown) couples to the partial ground 138. Accordingly, through soldering, an electrical connection may be established between the fifth part 108-5 at the front side 100F and the partial ground 138 at the back side 100B through the via (not shown) in the substrate 100S. Details of the partial ground is discussed in the
In an embodiment, the rectangular parasitic elements 102 are located at a distance of W6 units from the imaginary axis 136 on either side of the main rectangular patch segment 108. For example, the first rectangular parasitic element 102-1 is located at a distance of W6 units towards the third edge E3 and the second rectangular parasitic element 102-2 is symmetrically located at a distance of W6 units towards the fourth edge E3, respectively, from the imaginary axis 136. The location of the rectangular parasitic elements 102 with respect to the main rectangular patch segment 108 may depend upon an average of quarter wavelengths of each frequency that the SPA 100 is designed for. Based upon the average value of the resonating frequency, a quarter wavelength value may be calculated based on the relationship between the frequency and wavelength. Accordingly, the location of the rectangular parasitic element 102 is computed based upon the average of quarter wavelength of each frequency. In an embodiment, the length W6 is equal to 18.4 mm (±1.0 mm or preferably ±0.5 mm). The distance W6 is almost equal to one quarter wavelength from the imaginary axis 136 on each side of the main rectangular patch segment 108. In another embodiment, the distance between the rectangular parasitic elements 102 and the main rectangular patch segment 108 is equal to W11 units.
The front side 100F of the SPA 100 includes at least four biasing lines. The biasing line refers to a metallic strip disposed over the substrate 100S for biasing the three diodes over the main rectangular patch segment 108. For example, a first biasing line 126 including a first limiting resistor 126R and a first choke inductor 126L is electrically soldered to the first part 108-1 of the main rectangular patch segment 108. Similarly, a second biasing line 128 including a second limiting resistor 128R and a second choke inductor 128L is electrically soldered to the second part 108-2 of the main rectangular patch segment 108. Also, a third biasing line 130 including a third limiting resistor 130R and a third choke inductor 130L is electrically soldered to the third part 108-3 of the main rectangular patch segment 108. In the same way, a fourth biasing line 132 including a fourth limiting resistor 132R and a fourth choke inductor 132L is electrically soldered to the fourth part 108-4 of the main rectangular patch segment 108. In an embodiment, a length of each of biasing line is in between 7 and 8 mm and width is in between 1 and 3 mm. For example, each biasing line may have length of 7.6 mm and width of 2 mm. Adding the biasing lines ensure the radiation characteristics of the SPA 100 are not distorted. Also, as an example, value of each limiting resistor and each choke inductor are selected as 500M Ω and 68 nH, respectively. The limiting resistor in each biasing line limits the biasing current through the diodes in the main rectangular patch segment 108, since the diodes could be biased at no more than 0.7V. Also, the choke inductors in each biasing line isolates the RF signals from the DC supply such as a battery.
With reference to
The parasitic elements 102 are configured to act as a reflector or as a director according to bias settings of the diodes and the Yagi-Uda principle. According to the Yagi-Uda principle, an element, when placed at quarter wavelength from the center of the main radiating element, act as a reflector or director depending on the length of the element. Based on the Yagi-Uda principle, the reflector is configured to reflect all the radiated beams of the radiating element towards the director whenever the length of the reflector is more compared to the director, whereas the director is configured to concentrate the radiation beam. In the design of SPA 100, the main rectangular patch segment 108 acts as the main radiating element or a driving element, the first rectangular parasitic element 102-1 act as a first element and the second rectangular parasitic element 102-2 acts as a second element. The first element and the second element are configured to act either as a director or a reflector or vice versa. Both elements are placed at a quarter wavelength W6 units from the main rectangular patch segment 108. When the first diode 104 is turned ‘On’ and the second diode 106 is turned ‘Off’, the first section 102-1-1 and the second section 102-1-2 function as an element of length W4 units. The first rectangular parasitic element 102-1 thus acts as a reflector element, whereas the second rectangular parasitic element 102-2 acts as the director. On the other hand, when the first diode 104 is turned ‘Off’ and the second diode is turned ‘On’, the first section 102-1-1 and the second section 102-1-2 function as an element of length W4/2 units or less, whereas the third section 102-2-1 and the fourth section 102-2-2 acts an element of length W4 units. The first rectangular parasitic element 102-1 thus acts as a director element, whereas the second rectangular parasitic element 102-1 acts as a reflector element. The pattern reconfiguration in any direction is thus achieved since the surface current distribution of the SPA 100 is altered based upon the setting of all five diodes.
Plurality of the operating modes of the SPA 100 is now described in detail.
First mode settings: The first diode 104 is set to ‘1’, the second diode 106 is set to ‘0’, the third diode 120 is set to ‘1’, the fourth diode 122 is set to′1′, and the fifth diode 124 is set to ‘1’. Based on the settings, the first rectangular parasitic element 102-1 acts as a reflector and the second rectangular parasitic element 102-2 acts as a director as the length of the first rectangular parasitic element 102-1 is more compared to the second rectangular parasitic element 102-2. The SPA 100 resonates at 4.1 GHz. Also, the SPA 100 radiates at 143 degree of radiation angle.
Second mode settings: The first diode 104 is set to ‘0’, the second diode 106 is set to ‘1’, the third diode 120 is set to ‘1’, the fourth diode 122 is set to ‘1’, and the fifth diode 124 is set to ‘1’. Based on the settings, the first rectangular parasitic element 102-1 acts as a director and the second rectangular parasitic element 102-2 acts as a reflector as the length of the second rectangular parasitic element 102-2 is increased compared to the first rectangular parasitic element 102-1. The SPA 100 resonates at 4.1 GHz. According to the settings, the SPA 100 radiates at −143 degrees of radiation angle.
Third mode settings: The first diode 104 is set to ‘1’, the second diode 106 is set to ‘1’, the third diode 120 is set to ‘1’, the fourth diode 122 is set to ‘1’, and the fifth diode 124 is set to ‘1’. Based on the settings the first rectangular parasitic element 102-1 as well as the second rectangular parasitic element 102-2 have the same element length and none of them acts either as a director or a reflector. The SPA 100 resonates at 4.1 GHz. Based on settings, the SPA 100 radiates at 180 degrees of radiation angle.
Fourth mode settings: The first diode 104 is set to ‘1’, the second diode 106 is set to ‘1’, the third diode 120 is set to ‘1’, the fourth diode 122 is set to ‘0’, and the fifth diode 124 is set to ‘1’. As a result of the setting, the length of the radiating element, that is, the main rectangular patch segment 108 of the SPA 100 becomes shorter since one of the diode, (the fourth diode in this case) is set as off. Accordingly, the resonance frequency of the SPA 100 increases to 4.7 GHZ. Also, the first rectangular parasitic element 102-1 as well as the second rectangular parasitic element 102-2 have the same element length and none of them acts either as a director or a reflector. Further, the SPA 100 radiates at a radiation angle of 38 degree.
Fifth mode settings: The first diode 104 is set to ‘1’, the second diode 106 is set to ‘1’, the third diode 120 is set to ‘0’, the fourth diode 122 is set to ‘1’, and the fifth diode 124 is set to ‘1’. Based on the settings, the length of the radiating element, that is, the main rectangular patch segment 108 of the SPA 100 becomes shorter since one of the diode, (the third diode in this case) is set as off. The SPA 100 resonates at the resonance frequency of 4.7 GHZ. Also, the first rectangular parasitic element 102-1 as well as the second rectangular parasitic element 102-2 have the same element length and none of them acts either as a director or a reflector. Further, the SPA 100 radiates at a radiation angle of −38 degrees.
Sixth mode settings: The first diode 104 is set to ‘1’, the second diode 106 is set to ‘0’, the third diode 120 is set to ‘1’, the fourth diode 122 is set to ‘0’, and the fifth diode 124 is set to ‘1’. According to the settings, the length of the radiating element, that is, the main rectangular patch segment 108 of the SPA 100 becomes shorter since one of the diode, (the third diode in this case) is set as off. Also, the second rectangular parasitic element 102-2 acts as a reflector and the first rectangular parasitic element 102-1 acts as a director as the length of the second rectangular parasitic element 102-2 is increased compared to the first rectangular parasitic element 102-1. Accordingly, based upon the setting of all fives diodes, the SPA 100 resonates at the resonance frequency of 4.7 GHz with 63 degree of radiation angle.
Seventh mode settings: The first diode 104 is set to ‘0’, the second diode 106 is set to ‘1’, the third diode 120 is set to ‘0’, the fourth diode 122 is set to ‘1’, and the fifth diode 124 is set to ‘1’. According to the settings, the length of the radiating element, that is, the main rectangular patch segment 108 of the SPA 100 becomes shorter since one of the diode, (the fourth diode in this case) is set as off. Also, the first rectangular parasitic element 102-1 acts as a reflector and the second rectangular parasitic element 102-2 acts as a director as the length of the first rectangular parasitic element 102-1 is increased compared to the second rectangular parasitic element 102-2. Accordingly, based upon the setting of all fives diodes, the SPA 100 resonates at the resonance frequency of 4.7 GHZ with −63 degree of radiation angle.
Eighth mode settings: The first diode 104 is set to ‘1’, the second diode 106 is set to ‘1’, the third diode 120 is set to ‘0’, the fourth diode 122 is set to ‘0’, and the fifth diode 124 is set to ‘0’. According to the settings, the length of the radiating element, that is, the main rectangular patch segment 108 of the SPA 100 becomes even more shorter since two of the diode, (the third diode and the fourth diode in this case) is set as off. Also, the first rectangular parasitic element 102-1 as well as the second rectangular parasitic element 102-2 have the same element length and none of them acts either as a director or a reflector. Accordingly, based upon the setting of all fives diodes, the SPA 100 now resonates at the resonance frequency of 5 GHz with 0 degree of radiation angle.
Ninth mode settings: The first diode 104 is set to ‘1’, the second diode 106 is set to ‘0’, the third diode 120 is set to ‘0’, the fourth diode 122 is set to ‘0’, and the fifth diode 124 is set to ‘0’. According to the settings, the length of the radiating element, that is, the main rectangular patch segment 108 of the SPA 100 is as same as in the case of eighth mode. Also, the first rectangular parasitic element 102-1 acts as a reflector and the second rectangular parasitic element 102-2 acts as a director as the length of the first rectangular parasitic element 102-1 is increased compared to the second rectangular parasitic element 102-2. Accordingly, based upon the setting of all fives diodes, the SPA 100 resonates at the resonance frequency of 5 GHz with 50 degree of radiation angle.
Tenth mode settings: The first diode 104 is set to ‘0’, the second diode 106 is set to ‘1’, the third diode 120 is set to ‘0’, the fourth diode 122 is set to ‘0’, and the fifth diode 124 is set to ‘0’. According to the settings, the length of the radiating element, that is, the main rectangular patch segment 108 of the SPA 100 is as same as in the case of eighth mode or 9. Also, the first rectangular parasitic element 102-1 as well as the second rectangular parasitic element 102-2 have the same element length and none of them acts either as a director or a reflector. Accordingly, based upon the setting of all fives diodes, the SPA 100 resonates at the resonance frequency of 5 GHz with −50 degree angle of radiation.
Eleventh mode settings: The first diode 104 is set to ‘0’, the second diode 106 is set to ‘0’, the third diode 120 is set to ‘1’, the fourth diode 122 is set to ‘0’, and the fifth diode 124 is set to ‘1’. According to the settings, the length of the radiating element, that is, the main rectangular patch segment 108 of the SPA 100 is even shorter compared to previous cases. Also, the first rectangular parasitic element 102-1 as well as the second rectangular parasitic element 102-2 have the same element length and none of them acts either as a director or a reflector. Accordingly, based upon the setting of all fives diodes, the SPA 100 now resonates at the resonance frequency of 5.7 GHz with 90 degree angle of radiation.
Twelfth mode settings: The first diode 104 is set to ‘0’, the second diode 106 is set to ‘0’, the third diode 120 is set to ‘0’, the fourth diode 122 is set to ‘1’, and the fifth diode 124 is set to ‘1’. According to the settings, the length of the radiating element, that is, the main rectangular patch segment 108 of the SPA 100 is same as the previous cases. Also, the first rectangular parasitic element 102-1 as well as the second rectangular parasitic element 102-2 have the same element length and none of them acts either as a director or a reflector. Accordingly, based upon the setting of all fives diodes, the SPA 100 resonates at the resonance frequency of 5.7 GHZ with −90 degree angle of radiation.
Based upon the setting of all five diodes and the arrangement of the patch and the parasitic element, multiple frequencies between 4.1 GHz and 5.7 GHZ, that is, 4.7 GHZ and 5 GHz are radiated through the SPA 100. Accordingly, the SPA 100 radiates over at least 4 different resonance frequency bands, that is, 4.1 GHz, 4.7 GHZ, 5 GHz, and 5.7 GHZ with twelve different independent operating modes to reconfigure the direction of the radiation beam pattern through the SPA 100.
With reference to
Based upon
Table III shows the comparison of the SPA 100 with the antenna developed in prior art. The SPA 100 operates with an average gain of 3 dBi throughout the twelve independent modes based upon the simulated as well as prototype model of the SPA 100. Also, the average bandwidth of 13.9 GHz was obtained through the SPA 100 by the inventors based upon the experimental calculations. Moreover, the area of the SPA 100 is 50 mm (±5 mm, preferably ±2 mm)×50 mm (±5 mm, preferably ±2 mm) or less than 55×55 mm2. It is obvious that the SPA 100 has a simple antenna size, more operational modes, better average efficiency, moderately average gain, and comparatively better average bandwidth compared to all the antennas developed in the prior art. This makes the SPA 100 a viable choice for WiMAX applications.
Embodiments of the disclosure are illustrated with respect to
In an aspect, the SPA 100 further includes four biasing lines, that is, the first biasing line 126, the second biasing line 128, the third biasing line 130 and the fourth biasing line 132, each of length 6 mm (±1.0 mm). and width 2 mm (±1.0 mm).
In an aspect, the four biasing lines each include a limiting resistor (that is, the first limiting resistor 126R, the second limiting resistor 128R, the third limiting resistor 130R and the fourth limiting resistor 132R) and a choke inductor (that is, the first choke inductor 126L, the second choke inductor 128L, the third choke inductor 130L and the fourth choke inductor 132L).
In an aspect, the SPA 100 supports at least four frequency bands.
In an aspect, the SPA 100 is reconfigurable to 12 independent modes.
In an aspect, the SPA 100 has efficiency of at least 92% while configured to transmit at 5 GHz.
In an aspect, the SPA 100 operates with average gain of 3 dBi throughout the twelve independent modes.
In an aspect, the SPA 100 operates with average efficiency of 77%, throughout the 12 independent modes.
In an aspect, the SPA 100 includes a back view 100B wherein the back view 100B includes a partial ground 138 with one dimension 3 mm (±0.5 mm). and a second dimension 23.5 mm (±1.5 mm).
In an aspect, the back view 100B further includes a coaxial feed 140 that is placed between 11 mm (±1.0 mm).mm from the top of the partial ground 138.
In an aspect, the SPA 100 is less than 50 mm (±5.0 mm).×50 mm (±5.0 mm). in area.
To this end, the present disclosure describes a compact frequency and pattern reconfigurable segmented path antenna (SPA). The SPA includes 2 slits, 3 slot and 3 integrated PIN diodes in the slots to increase or decrease the length of the main rectangular patch segment in order to perform frequency reconfiguration. The SPA further includes two integrated diodes in the rectangular parasitic element in order to achieve pattern reconfiguration using the Yagi-Uda principle. The SPA therefore exhibits twelve operational modes in four frequency band merely by using five PIN diodes. Further, the SPA has a miniaturized structure having size less than 55×55 mm2. The SPA is simple to manufacture that makes the SPA best suited for WiMAX related applications.
Obviously, numerous modifications and variations of the present disclosure will be apparent to the person skilled in the art in light of the above description. For example, the shape of the main rectangular patch segment and the parasitic element may be circular, semi-circular, or triangular. Also, the length and width of the main rectangular patch segment and the parasitic element may have a certain tolerance value compared to the values used in the present disclosure. It is therefore to be understood that within the scope of the appended claims, the disclosure may be practiced otherwise than as specifically described herein.
The present application is a Continuation of U.S. application Ser. No. 17/879,847, now allowed, having a filing date of Aug. 3, 2022.
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| Entry |
|---|
| Panusa, et al ; Quad Band H-slot Microstrip Patch Antenna for WiMAX Application ; International Journal of Computer Applications, vol. 103, No. 12 ; Oct. 2014 ; 3 Pages. |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17879847 | Aug 2022 | US |
| Child | 18616304 | US |
