This application claims priority of Taiwanese Patent Application No. 107103738, filed on Feb. 2, 2018.
The disclosure relates to wireless communication, and more particularly to a full-duplex wireless transceiver.
A short distance radar apparatus may transmit and receive signals using a two-antenna scheme or a single-antenna scheme. For a conventional two-antenna short distance radar apparatus, two antennas are respectively used for transmitting and receiving, resulting in a relatively high hardware cost of the conventional two-antenna short distance radar apparatus. For a conventional single-antenna short distance radar apparatus, a single antenna is used for both transmitting and receiving, and a ferrite circulator is generally used for signal separation. The ferrite circulator cannot be fabricated by standard semiconductor process, resulting in a relatively high hardware cost of the conventional single-antenna short distance radar apparatus.
Therefore, an object of the disclosure is to provide a wireless transceiver that is operatively associated with a single antenna, and that can be used in a short distance radar apparatus to reduce a hardware cost of the same.
According to the disclosure, the wireless transceiver includes a switching amplifier and a current provider. The switching amplifier has a first port, a second port that is used to be coupled to an antenna, and a power port. The current provider is coupled to the power port of the switching amplifier, provides a current to the switching amplifier, and further provides an impedance to the switching amplifier such that an impedance of the switching amplifier at the second port matches an impedance of the antenna. The switching amplifier is for receiving a transmit signal input at the first port thereof, and is further for receiving a receive signal from the antenna at the second port thereof. The switching amplifier simultaneously amplifies the transmit signal input to generate a first output signal at the second port thereof for receipt by the antenna, and mixes the receive signal with the transmit signal input to generate, at the power port thereof, a second output signal having a frequency lower than that of the receive signal.
Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiments with reference to the accompanying drawings, of which:
Before the disclosure is described in greater detail, it should be noted that where considered appropriate, reference numerals or terminal portions of reference numerals have been repeated among the figures to indicate corresponding or analogous elements, which may optionally have similar characteristics.
Referring to
Referring to
In this embodiment, the current provider 3 provides the impedance to the switching amplifier 2 at a relatively low frequency band (ranging from several KHz to several MHz and covering the frequency of the second output signal), such that the impedance of the switching amplifier 2 at the second port 21 matches the impedance of the antenna at a relatively high frequency band covering the frequency of the receive signal. In addition, the impedance provided by the current provider 3 to the switching amplifier 2 is related to a conversion gain of the switching amplifier 2 (i.e., a ratio of a voltage amplitude of the second output signal to a voltage amplitude of the receive signal). Moreover, the current provider 3 includes a current source 30 that is coupled to the power port 23 of the switching amplifier 2, and that provides the current and the impedance to the switching amplifier 2. As shown in
Referring to
From
where RS denotes the impedance of the antenna, Ron denotes an ON impedance of the switch (M1), and RL denotes the impedance provided by the current provider 3 to the switching amplifier 2. Impedance matching requires a reflection coefficient smaller than 10 dB, and therefore the matching between the impedances (ZRF,in, RS) is achieved when the impedance (ZRF,in) is greater than 0.52×RS and smaller than 1.92×RS
The impedance (Ron) is generally far smaller than the impedance (RS), and therefore the matching between the impedances (ZRF,in, RS) is achieved when the impedance (RL) is greater than 4.2×Ron.
From
where VIF denotes the voltage amplitude of the second output signal, and VRF denotes the voltage amplitude of the receive signal.
Referring to
Referring to
In the second embodiment, the transmit signal input includes a first transmit signal and a second transmit signal, and the switching amplifier 2 includes two switches (M1, M2), two inductors (L1, L2), a band-pass filter 24 and a bypass device 25. The switch (M1) has a first terminal, a second terminal that is grounded, and a control terminal that is coupled to the first port 22 for receiving the first transmit signal therefrom. The switch (M2) has a first terminal, a second terminal that is grounded, and a control terminal that is coupled to the first port 22 for receiving the second transmit signal therefrom. The inductor (L1) is coupled between the power port 23 and the first terminal of the switch (M1). The inductor (L2) is coupled between the power port 23 and the first terminal of the switch (M2). The band-pass filter 24 includes two capacitors (C1, C2), a balun (T0) and an inductor (L0). The capacitor (C1) is coupled between the first terminal of the switch (M1) and ground. The capacitor (C2) is coupled between the first terminal of the switch (M2) and ground. The balun (T0) has a balanced side that is coupled to the first terminals of the switches (M1, M2), and an unbalanced side. The inductor (L0) is coupled between the unbalanced side of the balun (T0) and the second port 21. The band-pass filter 24 has a passband that covers a frequency of each of the first and second transmit signals and the frequency of the receive signal, and that does not cover the frequency of the second output signal. The bypass device 25 includes a capacitor (C3) coupled between the power port 23 and ground, and cooperates with the inductors (L1, L2) to form a low-pass filter having a passband that covers the frequency of the second output signal, and that does not cover the frequency of each of the first and second transmit signals and the frequency of the receive signal.
It should be noted that in other embodiments, the transistor (M3) may be replaced by a resistor or a choke (e.g., an RF choke).
In transmit operation of the wireless transceiver of this embodiment, each of the switches (M1, M2) alternates between conduction and non-conduction based on the corresponding one of the first and second transmit signals to convert DC power from the current provider 3 into AC power of radio frequency. In receive operation of the wireless transceiver of this embodiment, the receive signal is converted into a differential signal pair by the balun (T0), and the differential signal pair is down-converted by the switches (M1, M2), filtered by the low-pass filter (formed by the inductors (L1, L2) and the capacitor (C3)), and combined at the power port 23. It should be noted that the impedance (RL) (see
In view of the above, for each of the aforesaid embodiments, since the wireless transceiver is operatively associated with a single antenna, and since no element (e.g., a ferrite circulator) is required to be coupled between the wireless transceiver and the antenna for signal separation, a short distance radar apparatus with the wireless transceiver and the antenna can have a relatively low hardware cost.
In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiments. It will be apparent, however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. It should also be appreciated that reference throughout this specification to “one embodiment,” “an embodiment,” an embodiment with an indication of an ordinal number and so forth means that a particular feature, structure, or characteristic may be included in the practice of the disclosure. It should be further appreciated that in the description, various features are sometimes grouped together in a single embodiment, Figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects, and that one or more features or specific details from one embodiment may be practiced together with one or more features or specific details from another embodiment, where appropriate, in the practice of the disclosure.
While the disclosure has been described in connection with what are considered the exemplary embodiments, it is understood that the disclosure is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
Number | Date | Country | Kind |
---|---|---|---|
107103738 A | Feb 2018 | TW | national |
Number | Name | Date | Kind |
---|---|---|---|
3519765 | Huber | Jul 1970 | A |
5057791 | Thompson | Oct 1991 | A |
5305469 | Camiade | Apr 1994 | A |
5590412 | Sawai | Dec 1996 | A |
7831214 | Stockmann | Nov 2010 | B1 |
7877063 | Kim | Jan 2011 | B2 |
8190099 | Berg | May 2012 | B2 |
8301186 | Gorbachov | Oct 2012 | B2 |
8514035 | Mikhemar et al. | Aug 2013 | B2 |
8989679 | Cercelaru | Mar 2015 | B2 |
9490866 | Goel et al. | Nov 2016 | B2 |
9590794 | Analui et al. | Mar 2017 | B2 |
9602155 | Chartier | Mar 2017 | B2 |
9755668 | Mandegaran et al. | Sep 2017 | B2 |
9762416 | Mandegaran | Sep 2017 | B2 |
10211797 | Roderick | Feb 2019 | B2 |
20020151281 | Izadpanah | Oct 2002 | A1 |
20020164971 | Weinholt | Nov 2002 | A1 |
20020197974 | Weinholt | Dec 2002 | A1 |
20040229573 | Krasser | Nov 2004 | A1 |
20100027568 | Rajendran | Feb 2010 | A1 |
Entry |
---|
J. Zhou, N. Reiskarimian and H. Krishnaswamy, “9.8 Re-ceiver with integrated magnetic-free N-path-filter-based non-reciprocal circulator and baseband self-interference cancella-tion for full-duplex wireless,” 2016 IEEE International Solid-State Circuits Conference (ISSCC), San Francisco, CA, 2016, pp. 178-180. |
D. J. van den Broek, E. A. M. Klumperink and B. Nauta, “19.2 A self-interference-cancelling receiver for in-band full-duplex wireless with low distortion under cancellation of strong TX leakage,” 2015 IEEE International Solid-State Circuits Conference—(ISSCC) Digest of Technical Papers, San Francisco, CA, 2015, pp. 1-3. |
D. Yang, H. Yüksel and A. Molnar, “A Wideband Highly In-tegrated and Widely Tunable Transceiver for In-Band Full-Duplex Communication,” Duplex Communication,⇄ in IEEE Journal of Solid-State Circuits, vol. 50, No. 5, pp. 1189-1202, May 2015. |
B. van Liempd et al., “A +70-dBm IIP3 Electrical-Balance Duplexer for Highly Integrated Tunable Front-Ends,” in IEEE Transactions on Microwave Theory and Techniques, vol. 64, No. 12, pp. 4274-4286, Dec. 2016. |
Number | Date | Country | |
---|---|---|---|
20190245587 A1 | Aug 2019 | US |