Dual-mode circuit and communication / localization device

Abstract

A circuit can comprise a mixer circuit and a switching device configured to control the mixer circuit such that, in a first switching state, the mixer circuit can be operated in a mixer mode in which an input signal is mixed with a mixer signal; and in a second switching state, one or more components of the mixer circuit are deactivated, so that the mixer circuit can be operated in an amplifier mode in which the mixer signal is amplified without changing its frequency.

Description

[0001] The invention relates to a dual-mode circuit and a communication / localization device.

[0002] Communication and localization technologies play a crucial role in daily life and the workplace. They are essential for a wide range of applications, such as Industry 4.0, 6G communication, robotics, and autonomous driving. In these areas, it is often necessary for communication and localization functions to be available within a single system.

[0003] Until now, hardware solutions for communication and localization have typically been designed as separate systems and only integrated into a single system during operation to enable both functions. However, this approach not only results in additional hardware costs but also increases system complexity. In contrast, a hardware solution that offers both communication and localization functions in a single, integrated system could reduce system complexity and also make such a system more compact.

[0004] Typically, a technique called "signal shape engineering" is used to address such problems. This technology utilizes conventional radar or communication front-end circuitry and a specially designed signal shape to implement a combined communication and localization function. The radio frequency (RF) signal shape used simultaneously contains information for both communication and localization. A disadvantage of signal shape engineering is that the signal shapes for communication and localization are designed differently and have different requirements. Combining communication and localization into a single signal shape limits the respective performance and can, for example, increase susceptibility to mutual interference. Data processing for such a system is also more complex than for a standard communication or localization system.

[0005] In J. Marin, M. Bernhardt, M. Heino, and T. Riihonen, "Monostatic FMCW Radar Architecture for Multifunction Full-Duplex Radios," 55th Assimilar Conference on Signals, Systems and Computers, Pacific Grove, CA, USA, pages 640 to 644, 2021, such a solution for joint communication and localization is described. This approach utilizes an FMCW (Frequency-Modulated Continuous-Wave) radar front-end circuit. A special FSK (Frequency-Shift-Keying)-modulated FMCW chirp (FSK-FMCW) is used for localization and communication.

[0006] In S. George, P. Sen, N. Barreto, and G. Fettweis, "Reconfigurable E-band Receiver Development for Joint Communication and Sensing," IEEE 12th Latin America Symposium on Circuits and Systems (LASCAS), Arequipa, Peru, pages 1 to 4, 2021, a reconfigurable approach with a switchable architecture is presented. Depending on the operating mode, the front-end circuit can select the necessary signal at the local oscillator (LO) input of the receiver mixer by means of an additional switch and coupler between the LO and the transmitted signal from the transmitter (TX). The time slots for communication and localization are time-interleaved by switching between them. This approach has the disadvantage of requiring additional switches and couplers, which increases cost, complexity, and chip area.

[0007] In L. Han and K. Wu, "24-GHz Integrated Radio and Radar System Capable of Time-Agile Wireless Communication and Sensing," IEEE Transactions on Microwave Theory and Techniques, Vol. 60, No. 3, pages 618 to 631, doi: 10.1109 / TMTT.2011.2179552, March 2012, a hybrid radar / communication front-end circuit is described in which switching between radar and communication modes occurs without an additional switch. Communication and localization are time-interleaved. In radar mode, the baseband generator produces FMCW chirps, and the chirp is upmixed. The upmixed chirp is routed via a coupler to the receive (RX) mixer and used there as a reference signal for FMCW localization. In communication mode, the transmitter (TX) and receiver (RX) cannot operate simultaneously. When TX is active, RX is switched off, or vice versa.When TX is active, a baseband generator produces baseband data, as is standard for TX communications. When RX is active, the baseband generator produces a constant-frequency signal, and this signal is upmixed using the local oscillator (LO). The upmixed signal f. h = f LO + f Basisband The signal is then routed through the coupler to the RX mixer, and the received signal is down-converted to baseband in the RX. At this point, the down-converted signal is not yet demodulated, since f h ≠ f LO The demodulation must then be performed externally. h It is then used again during demodulation. However, this has the disadvantage that full-duplex functionality is not possible in communication mode and demodulation must be performed externally.

[0008] WO 2023 / 221 542 A1 describes a 5G dual-band mixer with a gain function and a frequency mixing function.

[0009] EP 4 350 986 A1 describes a frequency mixer with a transconductance circuit connected to an input signal terminal. This circuit is configured to generate a differential signal according to an input signal from the input signal terminal and to output the differential signal via a first output terminal and a second output terminal of the transconductance circuit. The frequency mixer further comprises a switching circuit configured to perform frequency mixing on a local oscillator signal from the local oscillator signal terminal and the differential signal to generate a mixed signal, and to output the mixed signal via a first output terminal and a second output terminal of the switching circuit.The frequency mixer further comprises a load circuit connected to an output terminal and configured to provide a load; and an amplification circuit connected between the switching circuit and the load circuit and configured to amplify the mixed signal.

[0010] US 2007 / 0072561 A1 describes multiple power amplifiers in an RF front end coupled to multiple antennas without diversity between the power amplifiers and antennas. Diversity switches direct signals for transmission through a selected antenna to a power amplifier coupled to that selected antenna. Multiple LNAs are coupled to the different antennas in the same manner.

[0011] Lin Lu et al., "A 60-GHz highly reused joint radar-communication transceiver with reconfigurable dual-mode gilbert cells in 65-nm CMOS," IEEE Microwave and Wireless Technology Letters, 2024, 34 (6), pages 797 to 800, describe a dual-module circuit with a mixer circuit configured as a Gilbert cell. A differential local oscillator signal is applied to two upper transistor pairs of the Gilbert cell. A differential intermediate frequency signal is also applied to a lower transistor pair of the Gilbert cell. One transistor of the lower pair can be deactivated, thereby also deactivating one transistor pair of the upper pair. The first transistor of the deactivated upper pair is coupled to a first differential output terminal, and the second transistor of the deactivated upper pair is coupled to a second differential output terminal.

[0012] Exemplary embodiments of the invention are shown in the figures and are explained in more detail below.

[0013] They show Fig. 1 a conventional Gilbert cell; Fig. 2 a radio device according to various aspects of this revelation; Fig. 3 a dual-mode circuit according to various aspects of this revelation in a mixer mode; and Fig. 4 a dual-mode circuit according to different aspects of this revelation in an amplifier mode.

[0014] The following detailed description refers to the accompanying drawings, which form part thereof and illustrate specific embodiments in which the invention can be implemented. In this context, directional terminology such as "top," "bottom," "front," "back," "anterior," "rear," etc., is used with reference to the orientation of the described figure(s). Since components of embodiments can be positioned in a number of different orientations, the directional terminology serves only for illustration and is in no way limiting. It is understood that other embodiments may be used and structural or logical modifications may be made without deviating from the scope of protection of the present invention.It is understood that the features of the various exemplary embodiments described herein can be combined with one another, unless specifically stated otherwise. The following detailed description is therefore not to be interpreted in a limiting sense, and the scope of protection of the present invention is defined by the appended claims.

[0015] Within the scope of this description, the terms "connected," "attached," and "coupled" are used to describe both direct and indirect connections, direct or indirect links, and direct or indirect couplings. In the figures, identical or similar elements are labeled with identical reference symbols where appropriate.

[0016] In this description, "deactivating" or "switching off" a transistor for operating the mixer circuit in an amplifier mode means either completely preventing current flow through the transistor (except for a possible leakage current) or reducing the current flow through the transistor (so that, for example, a maximum of 70%, 60%, 50%, 40%, or 30% of the maximum current flow through the transistor is allowed). Reducing the current flow through the transistor will disable the mixer mode, but the signal being amplified, such as the oscillator signal, will still essentially be amplified.

[0017] Various aspects of this revelation integrate communication functions and localization functions (e.g. radar) into a common system, making such a system more compact and inexpensive than conventional systems.

[0018] In various aspects of this disclosure, a high-frequency (RF) front-end circuit is used for communication and localization purposes, taking advantage of the fact that RF communication front-end circuits in many electronic components exhibit a high degree of similarity with regard to the required sub-blocks within the system. The only difference, as illustrated, is that an RF transmitter front-end circuit (RF-TX) and an RF receiver front-end circuit (RF-RX) for communication purposes each require a mixer to upmix the baseband data to the RF channel at the transmitter and downmix it from the RF channel at the receiver. In contrast, an RF transmitter front-end circuit (RF-TX) for localization purposes (FMCW radar transmitter) does not include such a mixer.

[0019] Therefore, various aspects of this disclosure provide a circuit in the transmit (TX) path that can switch between a mixer mode and a normal amplifier mode. This enables the development of an RF front-end circuit suitable for both communication and localization tasks.

[0020] A dual-mode circuit is illustrated in various aspects, which is reconfigured by switching between a mixer mode (in which a signal to be sent is upmixed to a high frequency (RF frequency) for communication purposes) and an amplifier mode (in which, for example, an oscillator signal, such as a local oscillator signal, is amplified (without changing its frequency)).

[0021] Several aspects of this revelation can be seen in a specially configured Gilbert cell where each half of the two upper differential pairs of the Gilbert cell can be switched off. By switching off each half of the two upper differential pairs of the Gilbert cell, the dual-mode circuit transforms from a mixer to an oscillator signal (for example, a local oscillator (LO) signal) amplifier.

[0022] Fig. Figure 1 shows a conventional Gilbert cell 100. The Gilbert cell 100 comprises a first (differential) transistor pair 102 (with a first NMOS field-effect transistor (NMOS-FET) M1 and a second NMOS-FET M2) and a second (differential) transistor pair 104 (with a first NMOS-FET M3 and a second NMOS-FET M4). Furthermore, a differential local oscillator (LO) circuit 106 and an optional DC bias circuit 108 are provided.

[0023] The differential LO circuit 106 comprises a first LO-NMOS FET M5 and a second LO-NMOS FET M6. A source terminal of the first LO-NMOS FET M5 and a source terminal of the second LO-NMOS FET M6 are coupled to ground potential. A drain terminal of the first LO-NMOS FET M5 is connected to a source terminal of the first NMOS FET M1 of the first transistor pair 102 and to a source terminal of the second NMOS FET M2 of the first transistor pair 102. An oscillator (not shown in Fig. 1) generates a first differential LO sub-signal LO p and connects this to the gate terminal of the first LO-NMOS-FET M5. A drain terminal of the second LO-NMOS-FET M6 is connected to a source terminal of the first NMOS-FET M3 of the second transistor pair 104 and to a source terminal of the second NMOS-FET M4 of the second transistor pair 104. The oscillator generates a second differential LO partial signal LO nand feeds this to the gate terminal of the second LO-NMOS-FET M6.

[0024] A baseband processor (not shown) generates a first baseband partial signal BB. p a differential baseband signal, biased by a bias voltage V generated by the DC bias circuit 108 BB , and supply these to a gate terminal of the first NMOS-FET M1 of the first transistor pair 102 and to a gate terminal of the second NMOS-FET M4 of the second transistor pair 104. Furthermore, the baseband processor is configured to output a second baseband sub-signal BB. n to generate the differential baseband signal, biased by the bias voltage V generated by the DC bias circuit 108 BB , and supply these to a gate terminal of the second NMOS-FET M2 of the first transistor pair 102 and to a gate terminal of the first NMOS-FET M3 of the second transistor pair 104.

[0025] The signal (voltage and current) provided at a drain terminal of the first NMOS-FET M1 of the first transistor pair 102 and the signal (voltage and current) provided at a drain terminal of the first NMOS-FET M3 of the second transistor pair 104 are visibly added and connected to a first partial output (out) coupled to these terminals. p ) of a differential output. The signal (voltage and current) provided at a drain terminal of the second NMOS-FET M2 of the first transistor pair 102 and the signal (voltage and current) provided at a drain terminal of the second NMOS-FET M4 of the second transistor pair 104 are also figuratively added and output at a second partial output (out) coupled to these terminals. n ) of a differential output is provided.

[0026] The two transistor pairs 102, 104 of the Gilbert cell 100 thus act as mixers to mix the differential baseband signal (which has a baseband frequency or an intermediate frequency IF) with the differential oscillator signal (e.g. local oscillator signal LO) to a differential output signal that has a higher frequency than the baseband frequency or the intermediate frequency, for example a radio frequency (RF) of a radio signal to be transmitted at the differential output.

[0027] The conventional Gilbert cell 100 features two differential transistor pairs 102, 104 at the top for the differential baseband (BB) and intermediate frequency (IF) inputs, respectively, and one differential transistor pair M5, M6 at the bottom for the local oscillator (LO) input. The two upper differential transistor pairs 102, 104 share the same bias voltage V. BB, which is provided by the DC bias circuit 108.

[0028] Fig. Figure 2 shows a radio device 200 according to various aspects of this revelation.

[0029] As explained in detail below, the 200 radio device can be used for both communication and localization purposes, depending on the selected operating mode.

[0030] The radio device 200 can have a baseband processor 202 which is configured to transmit a differential baseband signal 204 (which, for example, is a first baseband sub-signal BB). p and a second baseband sub-signal BB n to generate (exhibits) and feed it to a dual-mode circuit 208, which is coupled to the baseband processor 202. The dual-mode circuit 208 is part of a transmit path 206.

[0031] The transmit path 206 optionally includes a filter 210 and a transmit amplifier 212 (for example, a power amplifier 212). The transmit amplifier 212 is connected to an antenna connector (also referred to as an antenna port) 214. The radio device 200 may also include an antenna 216 connected to the antenna connector 214. The antenna 216 may include one or more antennas, for example, an antenna array, such as a phased antenna array.

[0032] The dual-mode circuit 208 is set up to operate in a first operating mode or in a second operating mode, controlled by a control signal provided by a control circuit (not shown) (the control circuit may in an example be implemented by the baseband processor 202).

[0033] The dual-mode circuit 208 is configured in the first operating mode (hereinafter also referred to as mixer mode) to mix the received differential baseband signal 204 with an oscillator signal 220 (for example, a differential oscillator signal 220, for example, a differential local oscillator signal 220) generated by an oscillator circuit (for example, a differential oscillator circuit, for example, a differential local oscillator signal 220), hereinafter also referred to as differential mixer signal 220, and thus to generate a differential high-frequency signal 222.The optional filter 210 filters the differential high-frequency signal 222 supplied to it and generates a filtered differential high-frequency signal 224, which is then fed to the transmit amplifier 212. The transmit amplifier amplifies the received signal, thus generating a communication transmit signal 226, which is fed to the antenna 216 and transmitted via the antenna. In the first operating mode of the dual-mode circuit 208, the radio device 200 functions as a radio communication device.

[0034] Even though in these examples the oscillator circuit 220 is configured as a differential oscillator circuit 218 (and thus the oscillator signal 220 is also a differential oscillator signal 220), it may be provided in various aspects of this disclosure that the oscillator circuit 218 is configured as a single-ended oscillator circuit 218 (and thus the oscillator signal 220 is a single-ended oscillator signal (for example, a single-ended local oscillator signal)). In such a case, an additional circuit is connected between the oscillator circuit 218 and the dual-mode circuit 208 (not shown), which performs a single-ended-to-differential conversion from the single-ended oscillator signal (for example, the single-ended local oscillator signal).

[0035] Furthermore, it should be noted that, even though in these examples the dual-mode circuit 208 is configured as a differential dual-mode circuit 208 (and thus the high-frequency signal 222 is also a differential high-frequency signal 222), it may be provided in various aspects of this disclosure that an additional circuit is connected between the dual-mode circuit 208 and the filter 210 or the transmitting amplifier 212 (not shown), which performs a "differential-to-single-ended" conversion from the differential high-frequency signal so that the high-frequency signal 222 is a single-ended high-frequency signal.

[0036] Furthermore, it should be noted that, although in these examples the optional filter 210 is configured as a differential filter 210 (and thus the filtered high-frequency signal 224 is also a differentially filtered high-frequency signal 224), it may be provided in various aspects of this disclosure that the filter 210 is configured as a single-ended filter 210 (and thus the filtered high-frequency signal 224 is a single-ended filtered high-frequency signal 224). In such a case, an additional circuit is connected between the filter 210 and the transmitting amplifier 212 (not shown), which performs a single-ended-to-differential conversion from the single-ended high-frequency signal if the transmitting amplifier 212 has a differential input.

[0037] The dual-mode circuit 208 is further configured, in its second operating mode (hereinafter also referred to as amplifier mode), to amplify the oscillator signal 220 generated by the oscillator circuit 218 without changing its frequency, thus generating an oscillator amplification signal 228. The optional filter 210 filters the incoming oscillator amplification signal 228 and generates a filtered oscillator amplification signal 230, which it feeds to the transmit amplifier 212. The transmit amplifier amplifies the received signal, thereby generating a localization transmit signal 232, which it feeds to the antenna 216 and transmits. In the second operating mode of the dual-mode circuit 208, the radio device 200 functions as a radio localization device.

[0038] It should be noted that in the second operating mode (or amplifier mode) the baseband signal 204 is either not generated or switched off or simply not processed by the dual-mode circuit 208.

[0039] The radio device 200 may further comprise a receive path 234. The receive path 234 may be connected to the antenna connector 214. The receive path 234 may comprise a receive amplifier 236 (for example, configured as a low-noise amplifier - LNA). The receive amplifier 236 may be configured to amplify a radio signal 238 received by means of the antenna 216 and to generate an amplified received radio signal 240, which is then fed to an optional receive filter 242 of the receive path 234.The receive path 234 can further comprise a circuit 244 which, depending on the receive mode of the radio device, mixes a filtered, amplified received radio signal 246 (or the amplified received radio signal 240) supplied by the optional receive filter 242 with the oscillator signal 220 (for example, the differential oscillator signal 220, for example, the differential local oscillator signal 220) down to the intermediate frequency or the baseband frequency and supplies the downmixed signal 248 to the baseband processor 202 for further signal processing (in the case where the received radio signal 238 is a high-frequency radio signal, i.e., a communication signal – i.e., in the case where the radio device 200 operates as a radio communication device).

[0040] Even in the case where the received radio signal 238 is a localization signal (e.g., a radar radio signal), the circuit (amplified or unamplified) 244 acts as a mixer and downmixes the filtered, amplified received radio signal 246 to, for example, the baseband frequency (or the intermediate frequency), which is then fed to the baseband processor 202 for further signal processing. In this case, the radio device 200 acts as a radio localization device.

[0041] A Tx-Rx isolator (also referred to as transmit-receive path isolator) may be provided at or near the antenna connector 214 (not shown in Fig. 2) which is configured to electrically isolate the transmit path 206 and the receive path 234 from each other without impairing their respective functions (for example, to route a signal to be transmitted from the transmit amplifier 212 of the transmit path 206 directly to the antenna 216, but to prevent any signal component of the signal to be transmitted from the receive path 234 – and / or, for example, to route a received signal from the antenna 216 directly to the receive amplifier 236 of the receive path 234, but to prevent any signal component of the received signal from the transmit path 206). The Tx-Rx isolation element can, for example, include or be formed by a circulator circuit.

[0042] Architecturally, a communications front-end circuit differs from a radar front-end circuit (which operates using FMCW) only by the presence of the upmixer in the transmit path (e.g. transmit path 206 (TX)).

[0043] In accordance with various aspects of the disclosure, a dual-mode circuit is provided that can be switched between a mixer and a pass-through amplifier. This allows existing radar (for localization) and communication system architectures to be used directly without major modifications or additional components. The dual-mode circuit, as described in various aspects of this disclosure, can include a specially configured Gilbert cell in which one half of the two upper differential transistor pairs (e.g., transistor pairs 302, 304) can be switched off (for example, the half with positive polarity or the half with negative polarity). The differential LO signal is fed to the source / emitter terminals of the transistors of the two upper differential transistor pairs.By switching off each half of the two upper differential transistor pairs, the dual-mode circuit transforms from a mixer to a LO signal amplifier.

[0044] Fig. Figure 3 shows the dual-mode circuit 208. Fig. 2 in greater detail. Fig. Figure 3 shows the dual-mode circuit 208 in its first operating mode, the mixer mode. Furthermore, in Fig. 3 An example of the oscillator circuit 218 is shown in greater detail.

[0045] The dual-mode circuit 208 features a Gilbert cell 300 (as an example of a mixer circuit). The Gilbert cell 300 features a first (differential) transistor pair 302 (with a first NMOS field-effect transistor (NMOS-FET) M1 and a second NMOS-FET M2) and a second (differential) transistor pair 304 (with a first NMOS-FET M3 and a second NMOS-FET M4).

[0046] Various aspects are explained using a CMOS (Complementary Metal Oxide Semiconductor) implementation; however, these aspects are not limited to CMOS. Therefore, the transistors do not necessarily have to be field-effect transistors. Bipolar transistors, for example, can be used as an alternative. Furthermore, in alternative examples, PMOS field-effect transistors can be used instead of NMOS field-effect transistors (in this example, the electrical potentials must, of course, be adjusted accordingly).

[0047] Furthermore, the dual-mode circuit 208 has a switching device 306 which is configured to control the mixer circuit, e.g. the Gilbert cell 300, such that - in a first switch state, the mixer circuit can be operated in a mixer mode in which an input signal is mixed with a mixing signal, and - in a second switch state, one or more components of the mixer circuit are deactivated, so that the mixer circuit can be operated in an amplifier mode in which the mixing signal is amplified without changing its frequency.

[0048] It should be noted that the switching device 306 can be implemented partially or completely in software (for example, one or more switches can be implemented by means of a corresponding computer program in a programmable processor) or partially or completely in hardware.

[0049] The oscillator circuit 218, for example, includes a differential local oscillator (LO) circuit 218.

[0050] The differential LO circuit 218 can comprise a first LO-NMOS-FET M5 and a second LO-NMOS-FET M6. A source terminal of the first LO-NMOS-FET M5 and a source terminal of the second LO-NMOS-FET M6 are coupled to a reference potential, for example, ground potential. A drain terminal of the first LO-NMOS-FET M5 is connected to a source terminal of the first NMOS-FET M1 of the first transistor pair 302 and to a source terminal of the second NMOS-FET M2 of the first transistor pair 302. An oscillator (not shown in Fig. 3) generates a first differential LO partial signal LO p and feeds this to the gate terminal of the first LO-NMOS-FET M5.

[0051] A drain terminal of the second LO-NMOS-FET M6 is connected to a source terminal of the first NMOS-FET M3 of the second transistor pair 304 and to a source terminal of the second NMOS-FET M4 of the second transistor pair 304. The oscillator generates a second differential LO partial signal LO n and feeds this to the gate terminal of the second LO-NMOS-FET M6.

[0052] The switching device 306 can have a first switch 308 and a second switch 310. The first switch 308 can have a first switching state and a second switching state. The second switch 310 can have a first switching state and a second switching state.

[0053] A control unit, for example the baseband processor 202 or an additional controller (not shown) can control the first switch 308 and the second switch 310 and selectively switch back and forth between the respective switch states and thus set the operating modes (first operating mode or second operating mode of the dual-mode circuit 208) of the dual-mode circuit 208.

[0054] The control can be configured to set the first operating mode (mixer mode), to put the first switch 308 into the first switch state and thus, for example, to apply a first partial bias voltage V to a first output of the dual-mode circuit 208. BBp from a bias voltage V supplied to the dual-mode circuit 208 BB(for example, from the baseband processor 202) to generate and provide. The first output is connected (for example, directly) to a first differential input 312. The first differential input 312 is configured to receive the first baseband partial signal BB. p of the differential baseband signal 204 from the baseband processor 202. The first differential input 312 and the first output of the dual-mode circuit 208 are connected to the gate terminal of the first NMOS-FET M1 of the first transistor pair 302 and to the gate terminal of the second NMOS-FET M4 of the second transistor pair 304.

[0055] The control can also be configured to set the second switch 310 to the first switch state in order to set the first operating mode (mixer mode) and thus, for example, apply a second partial bias voltage V to a second output of the dual-mode circuit 208. BBnfrom the bias voltage V supplied to the dual-mode circuit 208 BB (for example, from the baseband processor 202) to generate and provide. The second output is connected (for example, directly) to a second differential input 314. The second differential input 314 is configured to receive the second baseband partial signal BB. n of the differential baseband signal 204 from the baseband processor 202. The second differential input 314 and the second output of the dual-mode circuit 208 are connected to the gate terminal of the second NMOS-FET M2 of the first transistor pair 302 and to the gate terminal of the first NMOS-FET M3 of the second transistor pair 304.

[0056] The signal (voltage and current) provided at a drain terminal of the first NMOS-FET M1 of the first transistor pair 302 and the signal (voltage and current) provided at a drain terminal of the first NMOS-FET M3 of the second transistor pair 304 are visibly added and connected to a first partial output (out) coupled to these terminals. p ) of a differential output. The signal (voltage and current) provided at a drain terminal of the second NMOS-FET M2 of the first transistor pair 302 and the signal (voltage and current) provided at a drain terminal of the second NMOS-FET M4 of the second transistor pair 304 are also figuratively added and connected to a second partial output (out) coupled to these terminals. n ) of the differential output provided.

[0057] The two transistor pairs 302, 304 of the Gilbert cell 300 thus act in the first operating mode as a mixer to mix the differential baseband signal (which has a baseband frequency or an intermediate frequency IF) with the differential oscillator signal (e.g. local oscillator signal LO) to a differential output signal that has a higher frequency than the baseband frequency or the intermediate frequency, for example a radio frequency (RF) of a radio signal to be transmitted at the differential output.

[0058] In the first operating mode, all transistors of the two transistor pairs 302 and 304 are activated (in other words, electrically conductive and thus switched on), since an electrical voltage greater than the threshold voltage of each transistor is applied to the gate terminals of all transistors (NMOS FETs M1, M2, M3, M4) of the two transistor pairs 302 and 304. Thus, in this operating mode, the Gilbert cell 300 functions as a "normal" mixer circuit.

[0059] Fig. Figure 4 shows the dual-mode circuit 208. Fig. 3 in the second operating mode, the amplifier mode.

[0060] The control can be configured to set the first switch 308 to the first switch state in order to set the second operating mode (amplifier mode), and thus apply, for example, the first partial bias voltage V to the first output of the dual-mode circuit 208. BBpfrom the bias voltage V supplied to the dual-mode circuit 208 BB (for example, from the baseband processor 202) to generate and provide. The first output is connected (for example, directly) to the first differential input 312. The first differential input 312 is configured to receive the first baseband partial signal BB. p of the differential baseband signal 204 from the baseband processor 202. The first differential input 312 and the first output of the dual-mode circuit 208 are connected to the gate terminal of the first NMOS-FET M1 of the first transistor pair 302 and to the gate terminal of the second NMOS-FET M4 of the second transistor pair 304.

[0061] The control can also be configured to set the second switch 310 to the second switch state in order to set the second operating mode (amplifier mode) and thus connect the second output of the dual-mode circuit 208 to a reference potential 404 (in other words, a defined voltage level), for example to ground potential, and thus, in a visual sense, short-circuit the second differential input 314 and the gate terminal of the second NMOS-FET M2 of the first transistor pair 302 and the gate terminal of the first NMOS-FET M3 of the second transistor pair 304.

[0062] In the second operating mode of this variant, the first NMOS-FET M1 of the first transistor pair 302 and the second NMOS-FET M4 of the second transistor pair 304 are activated (in other words, electrically conductive and thus switched on), because an electrical voltage is applied to the gate terminals of these transistors (NMOS-FETs M1 and M4) that is greater than the threshold voltage of the respective transistors M1 and M4. Furthermore, in the second operating mode of this variant, the second NMOS-FET M2 of the first transistor pair 302 and the first NMOS-FET M3 of the second transistor pair 304 are deactivated (in other words, electrically insulated and thus switched off), because an electrical voltage is applied to the gate terminals of these transistors (NMOS-FETs M1 and M4) (for example, short-circuited) that is below the threshold voltage of the respective transistors M2 and M3.

[0063] Thus, in this (second) operating mode, the Gilbert cell 300 functions as an amplifier to amplify the differential LO signal.

[0064] In another variant, switches 308 and 310 can be connected as follows to implement the second operating mode.

[0065] In this variant, the control can further be configured to set the second operating mode (amplifier mode) by moving the first switch 308 to the second switch state and thus connecting the first output of the dual-mode circuit 208 to a reference potential 402 (in other words, a defined voltage level), for example to ground potential, and thus, in a visual sense, short-circuiting the first differential input 312 and the gate terminal of the first NMOS-FET M1 of the first transistor pair 302 and the gate terminal of the second NMOS-FET M4 of the second transistor pair 304.

[0066] In this variant, the control can also be configured to set the second switch 310 to the first switch state in order to set the second operating mode (amplifier mode) and thus, for example, apply the second partial bias voltage V to the second output of the dual-mode circuit 208. BB , from the bias voltage V supplied to the dual-mode circuit 208 BB (for example, from the baseband processor 202) to generate and provide. The second output is connected (for example, directly) to the second differential input 314. The second differential input 314 is configured to receive the second baseband partial signal BB. nof the differential baseband signal 204 from the baseband processor 202. The second differential input 314 and the second output of the dual-mode circuit 208 are connected to the gate terminal of the second NMOS-FET M2 of the first transistor pair 302 and to the gate terminal of the first NMOS-FET M3 of the second transistor pair 304.

[0067] Thus, in this variant, the Gilbert cell 300 also operates in the second operating mode as an amplifier to amplify the differential LO signal.

[0068] This circuit allows existing radar and communication system architectures to be used directly without major modifications or additional components. Existing radar methods and techniques (e.g., using FMCW) and communication can be applied directly.

[0069] In summary, according to various aspects of this disclosure, the bias voltage for the two upper differential transistor pairs 302, 304 is clearly separated and provided by a switching network (e.g., the switching device 306). As in Fig. 3 and Fig. As shown in Figure 4, in the first operating mode (mixer mode) the two nodes (e.g. the first output and the second output of the switching device 306) are connected with the first partial bias V BBp and the second partial preload V BBn supplied by the DC switching network (e.g. the switching device 306), wherein the DC switching network (e.g. the switching device 306) is supplied with the same bias voltage V BBis supplied. Thus, the two upper differential pairs are active (switched on). In amplifier mode, the bias voltage for one of the two nodes (e.g., the first output or the second output of the switching device 306) is supplied by the switching network (e.g., the switching device 306) from the bias voltage V. BBThe transistors are either separated or set to ground or a predefined voltage level (e.g., low for NMOS, higher for PMOS), thereby switching off half of the transistors (e.g., the first transistor M1 of the first transistor pair 302 and the second transistor M4 of the second transistor pair 304, or alternatively, the second transistor M2 of the first transistor pair 302 and the first transistor M3 of the second transistor pair 304). The switched-off transistors can be either the first transistor M1 of the first transistor pair 302 and the second transistor M4 (M1 and M4) or the second transistor M2 of the first transistor pair 302 and the first transistor M3 of the second transistor pair 304 (M2 and M3) in Fig. 3 and Fig. 4.

[0070] In Fig.Figure 4 shows the equivalent circuit of the dual-mode circuit 208 in the second operating mode (amplifier mode), in which the second transistor M2 of the first transistor pair 302 and the first transistor M3 of the second transistor pair 304 (M2 and M3) are switched off. It should be noted that the differential LO block 218 (e.g., the differential LO circuit 218) can be formed from a differential transistor pair or other circuit structures. The differential LO circuit 218 is configured to generate a differential LO voltage signal at the output of the LO circuit 218.

[0071] Some examples are presented below.

[0072] Example 1 is an integrated circuit. The integrated circuit may include a mixer circuit and a switching device configured to control the mixer circuit such that, in a first switch state, the mixer circuit can be operated in a mixer mode in which an input signal is mixed with a mixer signal; and in a second switch state, one or more components of the mixer circuit are deactivated, so that the mixer circuit can be operated in an amplifier mode in which the mixer signal is amplified without changing its frequency. The mixer circuit is configured as a Gilbert cell. The Gilbert cell comprises: a first transistor pair configured to receive a first mixer sub-signal of a differential mixer signal representing the mixer signal, and a second transistor pair configured to receive a second mixer sub-signal of the differential mixer signal.that a first transistor of the first transistor pair is coupled to a first output and is further configured to receive a first input sub-signal of a differential input signal, which represents the input signal; that a second transistor of the first transistor pair is coupled to a second output and is further configured to receive a second input sub-signal of the differential input signal; that a first transistor of the second transistor pair is coupled to the first output and is further configured to receive the second input sub-signal of the differential input signal; that a second transistor of the second transistor pair is coupled to the second output and is further configured to receive the first input sub-signal of the differential input signal;that the switching device is configured to deactivate the second transistor of the first transistor pair and the first transistor of the second transistor pair, or to deactivate the first transistor of the first transistor pair and the second transistor of the second transistor pair.

[0073] In Example 2, the subject of Example 1 may optionally include a switching device configured to apply a predefined reference potential to a control terminal of a respective transistor in amplifier mode to deactivate the respective transistor.

[0074] In Example 3, the item of either Example 1 or 2 may optionally include that the circuit further comprises an oscillator circuit configured to provide an oscillator signal (LO) as the mixed signal.

[0075] In Example 4, the subject of Example 3 may optionally include the oscillator circuit being configured to provide the oscillator signal as a differential mixed signal with a first mixed sub-signal and a second mixed sub-signal.

[0076] Example 5 is a communication device (figuratively, a communication / localization device, for example, a communication / radar device). The communication device may have: a transmit path for sending a transmit radio signal, wherein the transmit path includes a circuit according to one of Examples 1 to 4; and a receive path for receiving a receive radio signal.

[0077] In Example 6, the subject of Example 5 may optionally include a power amplifier circuit downstream of the transmission path.

[0078] In Example 7, the item may optionally include any of Examples 5 or 6, such that the receiving path further includes a low-noise amplifier circuit.

Claims

[1] Circuit comprising: a mixer circuit, and a switching device which is configured to control the mixer circuit such that • in a first switch state, the mixer circuit can be operated in a mixer mode in which an input signal is mixed with a mixing signal; and • in a second switch state, one or more components of the mixer circuit can be deactivated, so that the mixer circuit can be operated in an amplifier mode in which the mixing signal is amplified without changing its frequency. wherein the mixer circuit is configured as a Gilbert cell, wherein the Gilbert cell has: • a first transistor pair (M1, M2) for receiving a first mixed partial signal (LO) p ) of a differential mixed signal (LO p , LO n ), which represents the mixing signal, is set up, and • a second transistor pair (M3, M4) for receiving a second mixed partial signal (LO) n ) of the differential mixed signal (LO p , LO n ) is set up; • wherein a first transistor (M1) of the first transistor pair (M1, M2) is connected to a first output (out) p ) is coupled and furthermore for receiving a first input partial signal (BB) p ) of a differential input signal (BB p , BB n ), which represents the input signal, is set up; • wherein a second transistor (M2) of the first transistor pair (M1, M2) is connected to a second output (out n ) is coupled and furthermore for receiving a second input partial signal (BB) n ) of the differential input signal (BB p , BB n ) is set up; • where a first transistor (M3) of the second transistor pair (M3, M4) is connected to the first output (out) p) is coupled and furthermore for receiving the second input partial signal (BB) n ) of the differential input signal (BB p , BB n ) is set up; • where a second transistor (M4) of the second transistor pair (M3, M4) is connected to the second output (out n ) is coupled and furthermore for receiving the first input partial signal (BB) p ) of the differential input signal (BB p , BB n ) is set up; where the switch device is set up • to deactivate the second transistor (M2) of the first transistor pair (M1, M2) and the first transistor (M3) of the second transistor pair (M3, M4), or • to deactivate the first transistor (M1) of the first transistor pair (M1, M2) and the second transistor (M4) of the second transistor pair (M3, M4) . [2] Circuit according to claim 1, wherein the switching device is configured to apply a predefined reference potential to a control terminal of a respective transistor in amplifier mode to deactivate the respective transistor. [3] Circuit according to one of claims 1 or 2, further comprising: an oscillator circuit configured to provide an oscillator signal (LO) as the mixed signal. [4] Circuit according to claim 3, wherein the oscillator circuit is configured to output the oscillator signal as a differential mixed signal (LO p , LO n ) to provide with a first mixed partial signal (LO p ) and a second mixed sub-signal (LO n ). [5] Communication device comprising: • a transmission path for transmitting a transmit radio signal, wherein the transmission path comprises a circuit according to any one of claims 1 to 4; and • a receiving path for receiving a receiving radio signal. [6] Communication device according to claim 5, wherein the transmission path further comprises a power amplifier circuit downstream of the circuit. [7] Communication device according to claim 5 or 6, wherein the receive path further comprises a low-noise amplifier circuit.

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