This application claims priority to Chinese Application No. 201810011487.1 entitled “RADIO FREQUENCY TRANSCEIVER CIRCUIT WITH DISTRIBUTED INDUCTOR AND METHOD THEREOF,” filed on Jan. 5, 2018 by Beken Corporation, which is incorporated herein by reference.
The present application relates to circuits, and more particularly but not exclusively to a radio frequency (RF) transceiver circuit with distributed inductors.
A conventional RF circuit usually uses a discrete inductor as one of the electronic elements constituting the circuit. However, the product cost of the discrete inductor is relatively high and the utilization of the discrete inductor always affects the consistency of product performance of the printed circuit board (PCB).
To solve the above problems, a radio frequency transceiver circuit with distributed inductors may be necessary.
In an embodiment, a radio-frequency transceiver circuit comprises a first port and a second port, configured to, together, receive a pair of differential signals; a radio-frequency matching circuit, communicatively coupled to the first port and the second port, and configured to process the pair of differential signals to obtain a radio-frequency signal and increase transmission power for the radio-frequency signal, wherein the radio-frequency matching circuit includes at least one capacitor and at least one distributed inductor; a band pass filter circuit, communicatively coupled to the radio-frequency matching circuit and configured to filter the radio-frequency signal, wherein the band pass filter circuit includes at least one capacitor and at least one distributed inductor; and a third port, communicatively coupled to the band pass filter circuit and configured to output the filtered radio-frequency signal, wherein both of the at least one distributed inductors have a length of microstrip line.
Another embodiment discloses a method in the radio-frequency transceiver circuit comprises: receiving a pair of differential signals via a first port and a second port; processing, with a radio-frequency matching circuit, the pair of differential signals to obtain a radio-frequency signal and increasing transmission power for the radio-frequency signal, wherein the radio-frequency matching circuit is communicatively coupled to the first port and the second port and includes at least one capacitor and at least one distributed inductor; filtering, with a band pass filter circuit, the radio-frequency signal, wherein the band pass filter circuit is communicatively coupled to the radio-frequency matching circuit and includes at least one capacitor and at least one distributed inductor; and outputting the filtered radio-frequency signal via a third port, wherein the third port is communicatively coupled to the band pass filter circuit, and wherein both of the at least one distributed inductors have a length of microstrip line.
Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.
Various aspects and examples of the invention will now be described. The following description provides specific details for a thorough understanding and enabling description of these examples. Those skilled in the art will understand, however, that the invention may be practiced without many of these details. Additionally, some well-known structures or functions may not be shown or described in detail, so as to avoid unnecessarily obscuring the relevant description.
In the embodiment, the first port 110 is communicatively coupled to the second port 110 via the first capacitor C1. In the radio-frequency matching circuit 130, a first connection point among one end of the first capacitor C1, one end of the fourth capacitor C4 and the first port 110 is communicatively coupled to one end of the first distributed inductor L1. The other end of the first distributed inductor L1 is communicatively coupled to one end of the second capacitor C2. A second connection point among the other end of the first capacitor C1, one end of the sixth capacitor C6 and the second port 220 is communicatively coupled to one end of the second distributed inductor L2. The other end of the second distributed inductor L2 is communicatively coupled to one end of the third capacitor C3. A third connection point between the other end of the second distributed inductor L2 and one end of the third capacitor C3 is communicatively coupled to a fourth connection point between the other end of the first distributed inductor L1 and one end of the second capacitor C2. The fourth connection point is communicatively coupled to the voltage source. A fifth connection point between the other end of the third capacitor C3 and the other end of the second capacitor C2 is communicatively coupled to the ground. Furthermore, a connection point between the other end of the fourth capacitor C4 and one end of the fifth capacitor C5 is communicatively coupled to the ground via a third distributed inductor L3. A connection point between the other end of the sixth capacitor C6 and one end of the fourth distributed inductor L4 is communicatively coupled to the ground via the seventh capacitor C7.
In the embodiment, all of the distributed inductors L1-L4 have a length of microstrip line, wherein the length of microstrip line for manufacturing the first distributed inductor L1 or the second distributed inductor L2 is calculated according to
and the length of microstrip line for manufacturing the third distributed inductor L3 or the fourth distributed inductor L4 is calculated according to
and wherein the XL is a inductive reactance value of each distributed inductor and XL=2πf L, and wherein λ is a transmission wavelength value of signal transmitted in the microstrip line and λ=Vp×λVAC, and wherein the L is a inductance value of each distributed inductor and a value range of L is 1 nH-68 nH, and wherein Vp is a transmission speed value of signal transmitted in the microstrip line and λVAC is a transmission wavelength value of signal transmitted in vacuum. For example, L takes a value of 3.3 nH, f takes a value of 1.9 GHz, and the effective dielectric constant for the microstrip line is EEFF=3.01. Accordingly, XL=2πf L=39.4 ohm,
λVAC=11800/f=6210.5 mil, and λ=Vp×λVAC=3577.26 mil, and thus the length of L1 or L2 is
and the length of L3 or L4 is
In the embodiment, a connection point between the other end of the fifth capacitor C5 and the other end of the fourth distributed inductor L4 in the radio-frequency matching circuit 130 is communicatively coupled to a sixth connection point. The sixth connection point is among one end of the eighth capacitor C8, one end of the sixth distributed inductor L6 and one end of the ninth capacitor C9 in the band pass filter circuit 140. Further, in the band pass filter circuit 140, a seventh connection point between the other end of the sixth distributed inductor L6 and the other end of the ninth capacitor C9 is communicatively coupled to an eighth connection point between one end of the seventh distributed inductor L7 and the other end of the tenth capacitor C10. The seventh connection point and the eighth connection point are connected to the ground. The other end of the eighth capacitor C8 is communicatively coupled to the other end of the fifth distributed inductor L5. The other end of the seventh distributed inductor L7, the other end of the tenth capacitor C10 and one end of the fifth distributed inductor L5 are communicatively coupled to each other at a ninth connection point thereamong.
In the embodiment, all of the distributed inductors L5-L7 have a length of microstrip line, wherein the length of microstrip line for manufacturing the fifth distributed inductor L5, the sixth distributed inductor L6 or the seventh distributed inductor L7 is calculated according to
and wherein the XL is a inductive reactance value of each distributed inductor and XL=2πf L, and wherein λ is a transmission wavelength value of signal transmitted in the microstrip line and λ=Vp×λVAC, and wherein the L is a inductance value of each distributed inductor and a value range of L is 1 nH-68 nH, and wherein Vp is a transmission speed value of signal transmitted in the microstrip line and λVAC is a transmission wavelength value of signal transmitted in vacuum. For example, L takes a value of 3.3 nH, f takes a value of 1.9 GHz, and the effective dielectric constant for the microstrip line is EEFF=3.01. Accordingly, XL=2πf L=39.4 ohm,
λVAC=11800/f=6210.5 mil, and λ=Vp×λVAC=3577.26 mil, and thus the length of L5, L6 or L7 is
In one embodiment, the RF circuit 100 further comprises a switch 160 communicatively coupled to the third port 150 via an eighth distributed inductor L8 and a first resistor RI and configured to control the third port 150 to output the filtered radio-frequency signal, wherein a connection point between the switch 160 and the first resistor RI is communicatively coupled to the ground via a eleventh capacitor C11, and wherein a connection point between the first resistor RI and the eighth distributed inductor L8 is communicatively coupled to the ground via a twelfth capacitor C12, and wherein the ninth connection point is communicatively coupled to a connection point between the third port 150 and the eighth distributed inductor L8 via a thirteenth capacitor C13. In the embodiment, the filtered RF signal from the band pass filter circuit 140 is outputted via the third port 150 and then transmitted by the antenna communicatively coupled to the third port 150 as shown in the
In the embodiment, the distributed inductor L8 has a length of microstrip line, wherein the length of microstrip line for manufacturing the fifth distributed inductor L8 is calculated according to
and wherein the XL is a inductive reactance value of each distributed inductor and XL=2πf L, and wherein λ is a transmission wavelength value of signal transmitted in the microstrip line and λ=Vp×λVAC, and wherein the L is a inductance value of each distributed inductor and a value range of L is 1 nH-68 nH, and wherein Vp is a transmission speed value of signal transmitted in the microstrip line and λVAC is a transmission wavelength value of signal transmitted in vacuum. For example, L takes a value of 3.3 nH, f takes a value of 1.9 GHz, and the effective dielectric constant for the microstrip line is EEFF=3.01. Accordingly, XL=2πf L=39.4 ohm,
λVAC=11800/f=6210.5 mil, and λ=Vp×λVAC=3577.26 mil, and thus the length of L8 is
Since the distributed inductors in the RF circuit are manufactured by arranging the microstrip lines on the printed circuit board (PCB) directly, the manufacturing cost of the distributed inductors are much cheaper than that of the discrete inductors. Further, the inductance value error of the distributed inductors is much smaller than that of the discrete inductors, thus the consistency of the product performance of the PCB can be improved remarkably.
In one embodiment, the method 500 further comprises controlling (in block 540) the third port 250, 350 or 450 to output the filtered radio-frequency signal with the switch 460, wherein the switch 460 is communicatively coupled to the third port 450 via an eighth distributed inductor L8 and a first resistor R1, and wherein the eighth distributed inductor L8 has a length of microstrip line.
In the embodiment, all of the distributed inductors L1-L8 have a length of microstrip line, wherein the length of microstrip line for manufacturing the first distributed inductor L1, the second distributed inductor L2, the fifth distributed inductor L5, the sixth distributed inductor L6 or the seventh distributed inductor L7 is calculated according to
and the length of microstrip line for manufacturing the third distributed inductor L3, the fourth distributed inductor L4 or the eighth inductor L8 is calculated according to
and wherein the XL is a inductive reactance value of each distributed inductor and XL=2πf L, and wherein λ is a transmission wavelength value of signal transmitted in the microstrip line and λ=Vp×λVAC, and wherein the L is a inductance value of each distributed inductor and a value range of L is 1 nH-68 nH, and wherein Vp is a transmission speed value of signal transmitted in the microstrip line and λVAC is a transmission wavelength value of signal transmitted in vacuum. For example, L takes a value of 3.3 nH, f takes a value of 1.9 GHz, and the effective dielectric constant for the microstrip line is EEFF=3.01. Accordingly, XL=2πf L=39.4 ohm,
λVAC=11800/f=6210.5 mil, and λ=Vp×λVAC=35770.26 mil, and thus the length of L1 or L2 is
and the length of L3 or L4 is
Since the distributed inductors in the RF circuit are manufactured by arranging the microstip lines on the printed circuit board (PCB) directly, the manufacturing cost of the distributed inductors are much cheaper than that of the discrete inductors. Further, the inductance value error of the distributed inductors is much smaller than that of the discrete inductors, thus the consistency of the product performance of the PCB can be improved remarkably.
It should be appreciated by those ordinary skill in the art that components from different embodiments may be combined to yield another technical solution. This written description uses examples to disclose the invention, including the best mode, and also to enable any person ordinary skill in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
Number | Date | Country | Kind |
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2018 1 0011487 | Jan 2018 | CN | national |
Number | Name | Date | Kind |
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6064281 | Sheen | May 2000 | A |
6952142 | Guitton | Oct 2005 | B2 |
Number | Date | Country | |
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20190214960 A1 | Jul 2019 | US |