Reconfigurable wideband high-frequency circuits using non-reciprocal circulators

Abstract

A method includes receiving a radio frequency (RF) input signal using at least one non-reciprocal cyclic converter. The method also includes generating an RF output signal using at least one of one or more reflective circuit elements. Each reflective circuit element is configured to receive an RF signal from the at least one non-reciprocal cyclic converter and provide a modified RF signal to the at least one non-reciprocal cyclic converter. The RF output signal represents the RF input signal as modified by the at least one of the one or more reflective circuit elements.

Description

[Technical Field]

[0001] Cross-reference and priority claims of related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 034,617, filed June 4, 2020, pursuant to 35 USC § 119(e). Field of the Invention

[0003] This disclosure generally relates to communication systems. More specifically, this disclosure relates to reconfigurable broadband high-frequency circuits using non-reciprocal cyclic converters. [Previous Technology]

[0004] Background of the Invention

[0005] Wireless communication systems have become ubiquitous in today's society. In some situations, wireless communication systems need to have the ability to operate effectively within a wide range of operating frequencies. For example, various microwave communication systems can use frequencies in the range of 300 MHz to 300 GHz, and any individual microwave communication system may need to use frequencies within a wide subset of that frequency range. [Summary of the Invention]

[0006] Summary of the Invention

[0007] This disclosure relates to a reconfigurable broadband high-frequency circuit using a non-reciprocal cyclic converter.

[0008] In a first embodiment, a system includes at least one non-reciprocal cyclic converter and one or more reflective circuit elements. Each reflective circuit element is configured to receive a radio frequency (RF) signal from the at least one non-reciprocal cyclic converter and provide a modified RF signal to the at least one non-reciprocal cyclic converter.

[0009] In a second embodiment, a method includes receiving an RF input signal using at least one non-reciprocal cyclic converter. The method also includes generating an RF output signal using at least one of one or more reflective circuit elements. Each reflective circuit element is configured to receive an RF signal from the at least one non-reciprocal cyclic converter and provide a modified RF signal to the at least one non-reciprocal cyclic converter. The RF output signal represents the RF input signal as modified by at least one of the one or more reflective circuit elements.

[0010] In a third embodiment, a non-transitory computer-readable medium contains instructions that, when executed, cause at least one controller to reconfigure a system having at least one non-reciprocal circulator and a plurality of reflective circuit elements. Each reflective circuit element is configured to receive an RF signal from the at least one non-reciprocal circulator and to provide a modified RF signal to the at least one non-reciprocal circulator. The instructions causing the at least one controller to reconfigure the system include instructions that cause the at least one controller to change a sequence of non-overlapping pulses in control signals provided to a plurality of switches of each non-reciprocal circulator in order to selectively control which of the reflective circuit elements is electrically coupled to the at least one non-reciprocal circulator.

[0011] Other technical features will be obvious to those skilled in the art from the following figures, descriptions and the scope of the patent application.

Implementation Method

[0022] Detailed Description of Preferred Embodiments

[0023] Figures 1 to 9 described below, and the various embodiments used to illustrate the principles of this disclosure, are for illustrative purposes only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any type of suitably configured device or system.

[0024] As mentioned above, wireless communication systems have become ubiquitous in today's society. In some situations, wireless communication systems need to have the ability to operate effectively within a wide range of operating frequencies. For example, various microwave communication systems can use frequencies in the range of 300 MHz to 300 GHz, and any individual microwave communication system may need to use frequencies within a wide subset of that frequency range. As a specific example, a microwave communication system may need to be reconfigurable to operate or sweep in a frequency range of about 2 GHz to about 18 GHz. Typically, this requires the communication system to include various phase shifters, baluns, isolators, transceivers, or other circuit components that can be used at different times to handle different frequencies.

[0025] This disclosure provides various circuits based on non-reciprocal cyclic converters, which can be used to provide reconfigurable broadband high-frequency functionality, such as reconfigurable broadband high-frequency phase shifters, baluns, isolators, and transceivers. These circuits can be used in microwave front-ends or other larger systems.

[0026] As described in more detail below, some circuits based on a circulator typically include at least one non-reciprocal circulator and one or more reflective circuit elements (such as one or more reflective phase delay elements, reflective attenuators, or other reflective elements) coupled to the non-reciprocal circulator. The non-reciprocal circulator can receive a radio frequency (RF) input signal and provide the RF input signal to a first reflective circuit element, which can reflect the RF input signal back to the non-reciprocal circulator as a modified RF signal. If necessary, the modified RF signal can be provided to a second reflective circuit element, which can reflect the modified RF signal back to the non-reciprocal circulator as a modified RF signal. The non-reciprocal circulator can provide an RF output signal with one or more desired characteristics based on the modifications provided by the reflective circuit elements. The reflective circuit elements used to modify the RF input signal can be varied as needed, and different reflective circuit elements can be used over time to modify the RF input signal in different ways over time.

[0027] Other circulator-based circuits typically include at least one non-reciprocal circulator controlled to provide isolation functionality. This isolation functionality can be implemented without using any reflective circuitry elements. However, as described below, circulator-based circuits can be reconfigurable because the reflective circuitry elements used with at least one non-reciprocal circulator can be controllable. Therefore, it is possible to reconfigure a circulator-based circuit currently using one or more reflective circuitry elements to provide isolation functionality. It is also possible to reconfigure a circulator-based circuit currently providing isolation functionality to use one or more reflective circuitry elements to perform another function.

[0028] Depending on the implementation, the various circulator-based circuits disclosed herein can be highly reconfigurable and highly linear, for example, by using gallium nitride (GAN) implementations. Furthermore, in some cases, at least some of the reflective circuit elements can be selectively connected to and disconnected from the non-reciprocal circulator to provide the desired functionality. In this way, circulator-based circuits can be used to implement reconfigurable broadband high-frequency functions as needed in wireless communication systems or other systems.

[0029] Such circulator-based circuits can be used in any number of applications to support high-power or other wireless communications or other functionalities. For example, circulator-based circuits can be used in so-called "5G" base stations or other high-power base stations. As other examples, such circulator-based circuits can be used to replace various RF front-ends in various devices or implemented as transmit / receive module integrated circuits. However, it should be noted that circulator-based circuits can be used in any other suitable manner.

[0030] Figure 1 illustrates a circuit 100 based on a non-reciprocal circulator according to an example of this disclosure. As shown in Figure 1, circuit 100 typically includes at least one non-reciprocal circulator 102 and one or more reflective circuit elements 104a to 104n coupled to one of the non-reciprocal circulators 102. Depending on the implementation, circuit 100 may include a single non-reciprocal circulator 102 or multiple non-reciprocal circulators 102. Furthermore, any suitable number and type of reflective circuit elements 104a to 104n may be coupled to each non-reciprocal circulator 102. Additionally, if multiple non-reciprocal circulators 102 exist, the number and type of reflective circuit elements 104a to 104n coupled to the non-reciprocal circulators 102 may be the same or different.

[0031] Each non-reciprocal cyclic 102 includes a plurality of input / output (I / O) ports 106, wherein each I / O port is configured to receive and / or provide RF signals. Each non-reciprocal cyclic 102 is also configured to allow an RF signal received at one port 106 to travel in one direction (clockwise in this particular example) and be output via the next enabled or active port. In this example, the non-reciprocal cyclic 102 receives an RF input signal 108 at the first port 106, and the RF input signal 108 can be output to the first reflective circuit element 104a via the second port. The non-reciprocal cyclic 102 can also receive an input signal (representing a modified version of the signal previously output via the second port 106) at the second port 106, and the input signal can be output to the second reflective circuit element 104b via the third port. The final port 106 provides an RF output signal 110. Here, it should be noted that one, some, or all of the reflective circuit elements 104a to 104n may be used to convert the RF input signal 108 into the RF output signal 110, or all of the reflective circuit elements 104a to 104n may be disconnected from the non-reciprocal circulator 102, so that the non-reciprocal circulator 102 may be controlled to act as an isolator.

[0032] The non-reciprocal circulator 102 includes any suitable structure configured to allow RF signals to circulate non-reciprocally between different inputs and outputs. The phrase "non-reciprocal" indicates that the forward and reverse signals (meaning incoming and outgoing signals) at the same port travel through different paths, which helps to allow signals to move in a clockwise or counterclockwise direction (but not simultaneously). In some embodiments, the non-reciprocal circulator 102 represents a non-reciprocal circulator based on a field-effect transistor (FET) or other transistor. An example implementation of the non-reciprocal circulator 102 is described in Nagulu et al., “Ultra Compact, Ultra Wideband, DC-1GHz CMOS Circulator Based on Quasi-Electrostatic Wave Propagation in Commutated Switched Capacitor Networks,” 2020 IEEE Radio Frequency Integrated Circuits Symposium, August 2020, pp. 55-58 (which is hereby incorporated by reference in its entirety).

[0033] Each of the reflective circuit elements 104a to 104n is configured to modify the RF signal passing through the non-reciprocal circulator 102 and to provide the modified signal back to the non-reciprocal circulator 102. The exact composition and functionality of the reflective circuit elements 104a to 104n may vary depending on the implementation. For example, in some cases, the RF input signal 108 passes sequentially through all the reflective circuit elements 104a to 104n to achieve the desired signal modification and generate the desired RF output signal 110. In other cases, the RF input signal 108 passes sequentially through one or some (but not all) of the reflective circuit elements 104a to 104n to achieve the desired signal modification and generate the desired RF output signal 110, and the reflective circuit elements 104a to 104n used to modify the RF input signal 108 (such as based on the frequency of the RF input signal 108 or the RF output signal 110 and / or the desired signal modification) can be controlled. As a specific example, a transistor switch or other device may be used to selectively block or allow RF signals to pass between the non-reciprocal circulator 102 and each of the reflective circuit elements 104a to 104n. Each of the reflective circuit elements 104a to 104n is said to represent a different "branch" of the circuit 100.

[0034] Each of the reflective circuit elements 104a to 104n includes any suitable structure configured to modify the RF signal from the non-reciprocal cyclic unit 102 and provide the modified RF signal back to the non-reciprocal cyclic unit 102. Example implementations of reflective circuit elements 104a to 104n are provided below, wherein reflective circuit elements 104a to 104n are used to implement circuitry such as programmable phase shifters, programmable attenuators, and baluns. However, reflective circuit elements 104a to 104n can be used to provide any other desired functionality.

[0035] Although Figure 1 illustrates one example of a circuit 100 based on a non-reciprocal cyclic circuit, various modifications can be made to Figure 1. For example, each non-reciprocal cyclic circuit 102 may have any suitable number of ports 106 and be coupled to any suitable number of reflective circuit elements 104a to 104n. Furthermore, the various components in Figure 1 may be combined, further subdivided, copied, omitted, or reconfigured, and additional components may be added as needed.

[0036] Figure 2 illustrates an example of a circuit 200 based on a non-reciprocal cyclic converter supporting the balun function according to this disclosure. As shown in Figure 2, circuit 200 includes two non-reciprocal cyclic converters 102a to 102b and two reflective circuit elements 104a to 104b. Non-reciprocal cyclic converter 102a is configured to receive a portion of an RF input signal 108 and provide that portion of the RF input signal 108 to a phase delay element, which is implemented using a capacitor 202 coupled in series with an inductor 204 in reflective circuit element 104a. The phase-shifted RF signal is output as a first RF output signal 110a via non-reciprocal cyclic converter 102a. Non-reciprocal circulator 102b is configured to receive another portion of the RF input signal 108 and provide that portion of the RF input signal 108 to another phase delay element, which is implemented using a capacitor 206 coupled in series with the inductor 208 in the reflective circuit element 104b. The phase-shifted RF signal is output as a second RF output signal 110b via non-reciprocal circulator 102b.

[0037] Each capacitor 202, 206 includes any suitable capacitor structure providing any suitable capacitance. Each inductor 204, 208 includes any suitable inductor structure providing any suitable inductance. The specific values ​​of the capacitance and inductance here may vary based on the desired frequency response of the reflective circuit elements 104a to 104b. In some embodiments of circuit 200, non-reciprocal circulators 102a to 102b may each have a loss of about 0.1 dB and together provide about 20 dB of isolation between the RF output signals 110a to 110b. However, other embodiments may provide different levels of loss and isolation.

[0038] During operation, circuit 200 can generate two RF output signals 110a to 110b, which have substantially the same amplitude and a substantially 180° phase difference. The substantially equal amplitude can be achieved by splitting the RF input signal 108 into substantially equal parts and ensuring that the non-reciprocal cyclic circuits 102a to 102b and the reflective circuit elements 104a to 104b provide substantially the same signal amplitude attenuation. The substantially 180° phase difference can be achieved by designing the reflective circuit elements 104a to 104b to provide a relative phase shift, such that the total phase difference between the RF output signals 110a to 110b is approximately 180°.

[0039] Although Figure 2 illustrates an example of a non-reciprocal cyclic circuit 200 supporting balun functionality, various modifications can be made to Figure 2. For example, each reflector circuit element 104a to 104b may include any suitable type of phase shift element. As long as the phase shift difference between reflector circuit elements 104a and 104b is substantially 180° and the signal amplitude attenuation of non-reciprocal cyclic circuit elements 102a to 102b and reflector circuit elements 104a to 104b is substantially the same, differential RF signals can be created by RF output signals 110a to 110b to support balun functionality. Furthermore, various components in Figure 2 can be combined, further subdivided, copied, omitted, or reconfigured, and additional components can be added as needed.

[0040] Figure 3 illustrates an example of a non-reciprocal cyclic circuit 300 supporting a broadband reconfigurable phase shift according to this disclosure. As shown in Figure 3, circuit 300 includes a non-reciprocal cyclic circuit 102 and reflective circuit elements 104a to 104n. Here, each of the reflective circuit elements 104a to 104n implements a different phase-change reflector (PCR) 302, wherein each PCR 302 is configured to change the phase of the RF signal from the non-reciprocal cyclic circuit 102 and reflects the modified RF signal back to the non-reciprocal cyclic circuit 102. Essentially, the reflective circuit elements 104a to 104n here are acting as "phase-change" reflectors because they are changing the phase of the RF input signal 108. Each PCR 302 includes any suitable structure configured to provide a reflection with a phase shift, such as an inductor-capacitor (LC) circuit or a transmission line.

[0041] Each of the reflective circuit elements 104a to 104n can provide any suitable amount of phase delay. In some cases, the reflective circuit elements 104a to 104n all provide different amounts of phase delay. Using this circuit 300, a desired phase change can be obtained to meet the specific needs of a front-end system or other system. For example, a transistor switch or other device may be used to allow the RF input signal 108 to pass through one or more of the phase change reflectors 302 in one or more of the reflective circuit elements 104a to 104n, and the specific phase change reflector 302 used at any given time and the reflective circuit elements 104a to 104n can vary based on the desired phase change. In other words, the RF input signal 108 can be controllably passed through one or more branches of the circuit 300 to obtain the desired phase change. Furthermore, one or more branches of circuit 300 used to modify the RF input signal 108 can change over time, such as when a transistor switch or other device is controlled to change the reflective circuit elements 104a to 104n, which provide a phase shift to the RF input signal 108 over time. Thus, circuit 300 can be used to generate a broadband programmable phase shifter capable of operating within a wide range of desired phase transitions. Alternatively, if none of the reflective circuit elements 104a to 104n can be used to process the RF input signal 108 at a specified time, in which case circuit 300 can act as an isolator as described below.

[0042] Although Figure 3 illustrates one example of a non-reciprocal cyclic circuit 300 supporting broadband reconfigurable phase shift, various modifications can be made to Figure 3. For example, the non-reciprocal cyclic circuit 102 may have any suitable number of ports 106 and may be coupled to any suitable number of reflective circuit elements 104a to 104n, and each reflective circuit element 104a to 104n may include any suitable type of phase-change reflector. Furthermore, some of the reflective circuit elements 104a to 104n may include phase-independent components. Additionally, the various components in Figure 3 can be combined, further subdivided, copied, omitted, or reconfigured, and additional components can be added as needed.

[0043] Figure 4 illustrates another example of a broadband reconfigurable phase shift based on a non-reciprocal cyclic circuit 400 according to this disclosure. As shown in Figure 4, circuit 400 includes a non-reciprocal cyclic circuit 102, and reflective circuit elements 104a to 104n are implemented using a reference phase-change reflector 402a and a phase-shift reflector (PSR) 402b. RF signals can selectively pass through one of the reference phase-change reflectors 402a and one of the phase-shift reflectors 402b to obtain the desired phase shift (wherein the phase shift is defined by the phase shift difference between the two reflectors 402a and 402b). Broadband phase shifts can be achieved using this type of relative phase change. Each phase-change reflector 402a and each phase-shift reflector 402b includes any suitable structure, such as an LC circuit or transmission line, assembled to provide a reflection with a phase shift.

[0044] Each pair of reference phase-change reflectors 402a and phase-shift reflectors 402b can provide any suitable amount of phase delay. In some cases, different pairs of reference phase-change reflectors 402a and phase-shift reflectors 402b provide different amounts of phase delay. Using this circuit 400, a desired phase change can be obtained to meet the specific needs of a front-end system or other system. For example, a transistor switch or other device can be used to allow the RF input signal 108 to pass through one or more pairs of reflectors 402a to 402b, and the specific pairing of reflectors 402a to 402b used at any given time can vary based on the desired phase change. In other words, the RF input signal 108 can be controllably passed through one or more branches of the circuit 400 to obtain the desired phase change. Furthermore, the branch of circuit 400 used to modify one or more of the RF input signal 108 can change over time, such as when a transistor switch or other device is controlled to change multiple pairs of reflectors 402a to 402b, which are used to provide a phase shift to the RF input signal 108 over time. Thus, circuit 400 can be used to generate a broadband programmable phase shifter capable of operating over a wide range of desired phase transitions. In some cases, circuit 400 may produce fewer phase and amplitude errors compared to circuit 300, but these errors can vary depending on the implementation. Additionally, none of the reflectors 402a to 402b can be used to process the RF input signal 108 at a specified time; in this case, circuit 400 can act as an isolator as described below.

[0045] Although Figure 4 illustrates another example of a non-reciprocal cyclic circuit 400 supporting a broadband reconfigurable phase shift, various modifications can be made to Figure 4. For example, the non-reciprocal cyclic circuit 102 may have any suitable number of ports 106 and may be coupled to any suitable number of reflective circuit elements 104a to 104n, and each reflective circuit element 104a to 104n may include any suitable type of phase-change or shift reflector. Furthermore, some of the reflective circuit elements 104a to 104n may include phase-independent components. Additionally, the various components in Figure 4 can be combined, further subdivided, copied, omitted, or reconfigured, and additional components can be added as needed.

[0046] Figure 5 illustrates a specific example implementation of a non-reciprocal cyclic circuit 500 supporting a broadband reconfigurable phase shifter according to the present disclosure. In this specific implementation of the reconfigurable phase shifter, circuit 500 includes a reference phase change reflector 402a', a phase shift reflector 402b', a reference phase change reflector 402a'', and a phase shift reflector 402b''. The phase change reflector 402a' is implemented using series-coupled capacitors and inductors, and the phase shift reflector 402b' is implemented using parallel-coupled capacitors and inductors. Similarly, the phase change reflector 402a'' is implemented using series-coupled capacitors and inductors, and the phase shift reflector 402b'' is implemented using parallel-coupled capacitors and inductors.

[0047] Each capacitor includes any suitable capacitor structure providing any suitable capacitance, and each inductor includes any suitable inductor structure providing any suitable inductance. The specific values ​​of the capacitance and inductance here may vary based on the desired phase shift of the reflectors 402a', 402b', 402a'', 402b'' of the reflective circuit elements 104a and 104b.

[0048] In this example, circuit 500 uses LC reflectors to implement a multi-stage phase shifter. In some embodiments, reflectors 402a' and 402b' may be used to provide a 90° phase shift, and reflectors 402a'' and 402b'' may be used to provide a 180° phase shift. Therefore, circuit 500 can be programmed to provide: a 0° phase shift (by passing the signal through reflectors 402a', 402a'' and skipping reflectors 402b', 402b''), a 90° phase shift (by passing the signal through reflectors 402b', 402a'' and skipping reflectors 402a', 402b''), a 180° phase shift (by passing the signal through reflectors 402a', 402b'' and skipping reflectors 402a'', 402b''), or a 270° phase shift (by passing the signal through reflectors 402a'', 402b'' and skipping reflectors 402a', 402b''). It should be noted that the use of four reflectors to provide 0°, 90°, 180°, and 270° phase shifts is for illustrative purposes only. Any number of reflectors can be used here to provide different amounts of phase transition to the RF input signal 108.

[0049] Although Figure 5 illustrates a specific example of an implementation of a non-reciprocal cyclic circuit 500 supporting a broadband reconfigurable phase shift, various modifications can be made to Figure 5. For example, the non-reciprocal cyclic circuit 102 may have any suitable number of ports 106 and may be coupled to any suitable number of reflective circuit elements, and each reflective circuit element may include any suitable type of phase-change or shift reflector. Furthermore, some of the reflective circuit elements may include phase-independent components. Additionally, the various components in Figure 5 can be combined, further subdivided, copied, omitted, or reconfigured, and additional components can be added as needed.

[0050] Figures 6A and 6B illustrate an example of a non-reciprocal circulator 102 and its operation according to this disclosure. It should be noted that the same type of structure and operation can be used for each of the non-reciprocal circulators 102a to 102b discussed above. As shown in Figure 6A, the non-reciprocal circulator 102 includes at least one energy storage device 602 coupled to a common node 606 and a plurality of switches 604a to 604d. The energy storage device 602 includes any suitable structure configured to store and release electromagnetic energy, such as one or more capacitors or inductors (e.g., one or more high-Q capacitors or inductors). Each switch 604a to 604d is configured to close (become conductive) and open (become non-conductive) to selectively allow RF signals to pass through the switch. For example, switch 604a can be closed to provide an RF input signal 108 to the common node 606. One or more of switches 604b to 604c may be closed to provide an RF signal from the common node 606 to one or more reflective circuit elements 104a to 104n. Switch 604d may be closed to provide an RF output signal 110 from the common node 606. Each switch 604a to 604d includes any suitable structure, such as a FET or other transistor, configured to selectively form and prevent electrical connection.

[0051] It should be noted that although the non-reciprocal circulator 102 herein includes four switches 604a to 604d, this is for illustrative purposes only. The non-reciprocal circulator 102 may include fewer than four or more than four switches 604a to 604d depending on the implementation. For example, the non-reciprocal circulator 102 may include a switch for receiving an RF input signal 108, a switch for providing an RF output signal 110, and a switch for coupling to each of the reflective circuit elements 104a to 104n of the non-reciprocal circulator 102.

[0052] As shown in Figure 6B, timing diagram 650 illustrates an example operation of switches 604a to 604d of the non-reciprocal circulator 102. Here, timing diagram 650 includes a line 652 representing a control signal Fs1 for switch 604a, a line 654 representing a control signal Fs2 for switch 604b, a line 656 representing a control signal Fs3 for switch 604c, and a line 658 representing a control signal Fs4 for switch 604d. Each control signal includes a pulse 660 that defines when the associated switches 604a to 604d conduct.

[0053] As can be seen here, the pulses 660 in the control signals appear sequentially. In other words, the pulses 660 in different control signals do not overlap with each other, so only one of the switches 604a to 604d is conductive at any given time. The sequential use of pulses 660 in the control signals allows the RF signal to be transmitted in a circular manner via the non-reciprocal cyclic converter 102. In some embodiments, the pulses 660 appear in this continuous manner during repeated time intervals, wherein the period of the interval is denoted as Ts. Here, each pulse 660 may have a duration defined as Ts / N, where N represents the number of switches 604a to 604d actively used to transmit the RF input signal 108 to the desired reflective circuit elements 104a to 104n and output the RF output signal 110. Also, the energy storage device 602 here may generate reflection at a frequency of N×Fs, where Fs represents the frequency of the RF input signal 108.

[0054] It should be noted that the reconfiguration RF signal can be re-circulated through the non-reciprocal cyclic unit 102 by changing the sequence of the continuous pulses 660 in the control signal. Therefore, one or more branches of the circuitry leading to the non-reciprocal cyclic unit 102, followed by the RF signal during processing, can be altered by adjusting the sequence of the continuous pulses 660 in the control signal. The sequence of the continuous pulses 660 in the control signal can be controlled in any suitable manner, such as by using a processor or other control device.

[0055] The non-reciprocal circulator 102 can be implemented in any suitable manner using any suitable material. For example, in some embodiments, the ferrite-based non-reciprocal circulator 102 can be implemented using a single-junction or multi-junction approach, using a self-biased hex ferrite, or using lumped elements. In other embodiments, the electronically based non-reciprocal circulator 102 can be implemented using time-varying technology, can be based on a switch, or can be implemented using a sequentially switched delay line. The electronically based non-reciprocal circulator 102 can support N-way or N-path designs and represent a quasi-circuit or active circulator. The electronically based non-reciprocal circulator 102 can support linear time-varying operation or be used as an active or passive mixer. Other embodiments of the non-reciprocal circulator 102 can be based on a bulk acoustic wave device, a spin wave / topological insulator, or a Josephson junction. Additionally, embodiments of the non-reciprocal circulator 102 can be single-ended or differential.

[0056] Although Figures 6A and 6B illustrate one example of the non-reciprocal circulator 102 and its operation, various modifications can be made to Figures 6A and 6B. For example, the number of switches 604a to 604d and the associated control signals can be varied as needed. As a specific example, if the RF input signal 108 passes through one or some (but not all) of the reflective circuit elements 104a to 104n, the control signals for the used reflective circuit elements 104a to 104n may include continuous pulses, and the control signals for the unused reflective circuit elements 104a to 104n will not include pulses. Furthermore, any other suitable non-reciprocal circulator can be used in the circuit described in this patent document.

[0057] Figure 7 illustrates an example of a circuit 700 based on a non-reciprocal cyclic converter supporting isolator functionality according to this disclosure. As shown in Figure 7, circuit 700 includes a non-reciprocal cyclic converter 702 having at least one energy storage device 704 coupled to a common node 708 and a plurality of switches 706a to 706b. These components may be the same as or similar to the corresponding components in Figure 6A. Here, one switch 706a may be controlled by a clock signal (Clk), and another switch 706b may be controlled by the inverted () phase of the clock signal. When the clock signal has a 50% duty cycle, this results in switches 706a to 706b each conducting for substantially the same amount of time. The overall effect here is that RF input signal 710 can pass through circuit 700 and be output as RF output signal 712, while circuit 700 is used to effectively isolate the component providing RF input signal 710 from the component receiving RF output signal 712.

[0058] It should be noted that although reflective circuit elements 104a to 104n are not shown in FIG. 7, the common node 708 may be selectively coupled to one or more reflective circuit elements 104a to 104n via one or more additional switches (such as in the same or similar manner as shown in FIG. 6A). Thus, for example, circuit 700 may be configured to perform one or more functions using reflective circuit elements 104a to 104n, and then reconfigured to act as an isolator (or vice versa) via appropriate control of pulses provided to the switches of circuit 700. As a specific example, each of the non-reciprocal circulators described above or below in this patent document may be configured to act as an isolator by disconnecting the non-reciprocal circulator from its associated reflective circuit element and operating the two switches of the non-reciprocal circulator shown in FIG. 7. However, it should be noted that this is not necessarily required, and non-reciprocal circulator 702 may not be coupled to any reflective circuit element.

[0059] Although Figure 7 illustrates one example of a non-reciprocal cyclic circuit 700 supporting isolator functionality, various modifications can be made to Figure 7. For example, the non-reciprocal cyclic circuit 702 may have any suitable number of ports and may be coupled to any suitable number of reflective circuit elements 104a to 104n (excluding the reflective circuit elements), and each reflective circuit element 104a to 104n may include any suitable type of component. Furthermore, the various components in Figure 7 may be combined, further subdivided, copied, omitted, or reconfigured, and additional components may be added as needed.

[0060] Figures 8A to 8D illustrate an example architecture 800 supporting a non-reciprocal cyclic transceiver according to this disclosure. As shown in Figure 8A, architecture 800 includes a sequence of non-reciprocal cyclic transceivers 802a to 802j connected in series, each of which can operate in the same or similar manner as the non-reciprocal cyclic transceivers 102, 102a to 102b described above. The first non-reciprocal cyclic transceiver 802a is configured to receive a transmit RF input signal 804a or receive an RF input signal 804b and output the received signal to the next non-reciprocal cyclic transceiver 802b. Non-reciprocal cyclic transceivers 802i are configured to provide an RF signal to an amplifier 806, which amplifies the RF signal. The amplified RF signal is provided to the final non-reciprocal cyclic transceiver 802j and output as a transmit RF output signal 808a or a receive RF output signal 808b.

[0061] Various reflective circuit elements 810a to 810g and / or various reflective circuit elements 812a to 812i can be used to modify the RF input signal 804a or 804b. Here, reflective circuit elements 810a to 810g represent different phase delay elements and are configured to provide different amounts of phase delay to the RF input signal 804a or 804b. Similarly, reflective circuit elements 812a to 812i represent different attenuation elements and are configured to attenuate the RF input signal 804a or 804b by different amounts. Non-reciprocal circulators 802b to 802i can be used in the same manner described above to route RF input signals 804a or 804b as needed by one or more of reflective circuit elements 810a to 810g and / or one or more of reflective circuit elements 812a to 812i, so as to provide one or more desired phase transitions and / or one or more desired attenuations to RF input signals 804a or 804b when generating RF output signals 808a or 808b.

[0062] The control system 814 can be used for various operations within the control architecture 800. For example, the control system 814 can generate and output multiphase clock signals for controlling non-reciprocal cyclic processors 802a to 802j, such as four-phase clock signals used with four-port non-reciprocal cyclic processors. The control system 814 can also interact with other components via a Serial Peripheral Interface (SPI) or other interfaces. The control system 814 can further generate signals to enable or disable various components within the architecture 800. The control system 814 includes any suitable architecture configured to operate the control architecture 800, such as one or more microprocessors, microcontrollers, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or discrete circuit systems.

[0063] In architecture 800, all paths / branches for RF signals can be controlled via control system 814, and paths or branches can be selected or skipped using appropriate pulses or the absence of pulses for the switches in non-reciprocal cyclic circuits 802a to 802j. Most components in architecture 800 can be low-voltage components, and amplifier 806 can be used for both transmission and reception purposes. Each path or branch can inherently have a large minimum isolation (such as about 15 dB to about 20 dB or greater), which simplifies impedance matching and reduces or prevents impedance pulling between bits in incoming or outgoing data. The reflection phase shifter and attenuator functions may have lower losses compared to their "through-mode" counterparts. In some cases, complementary metal-oxide-semiconductor (CMOS) technology can be used to fabricate all digital components of architecture 800. All clock harmonics can be out-of-band and therefore easily filtered, and architecture 800 can operate in a highly linear manner. In addition, the transmission and reception paths here are completely shared and can be easily selected depending on the specific needs of any given time.

[0064] Figure 8B illustrates a portion of one example implementation of the control system 814. As shown in Figure 8B, the control system 814 may include at least one clock source 816, which can be used to generate non-overlapping control signals for the switching of non-reciprocal cyclic units 802a to 802j. Depending on the implementation, each non-reciprocal cyclic unit 802a to 802j may have its own clock source 816, or the clock source 816 may be shared among at least two of the non-reciprocal cyclic units 802a to 802j. In each clock source 816, an oscillator 818 operating at a desired frequency can be used to generate the clock signal, and a clock divider 820 (such as a CMOS clock divider) can be used to generate non-overlapping control signals for the associated non-reciprocal cyclic units 802a to 802j.

[0065] At least one controller 822 may be used to control the operation of clock sources 816 and other components of the possible architecture 800. For example, controller 822 may receive various information (such as measurements of the power or other characteristics of the transmitted or received RF output signal 808a or RF output signal 808b) and control the operation of clock sources 816 based on that information. As a particular example, controller 822 may sweep the frequency of each clock source 816 within a desired frequency range (such as about 2 GHz to about 18 GHz or some other suitable frequency range). For example, this may be used to help sense and counteract jammer signals. Controller 822 may also be used, or alternatively, to control the generation of continuous pulses in the control signals from clock sources 816. For example, controller 822 can determine which of the reflective circuit elements 810a to 810g, 812a to 812i are used to process the RF input signal 804a or 804b at a given time, and controller 822 can control the operation of clock divider 820 in clock source 816 to generate the required continuous pulses for switching of non-reciprocal cyclic units 802a to 802j. Depending on the implementation, each non-reciprocal cyclic unit 802a to 802j or clock source 816 may have its own controller 822, or controller 822 may be shared among at least two of the non-reciprocal cyclic units 802a to 802j or clock source 816.

[0066] Each controller 822 includes any suitable structure configured to control the operation of one or more components of architecture 800, such as by generating control signals via a control clock divider 820. For example, controller 822 may include one or more processing devices 824, such as one or more microprocessors, microcontrollers, DSPs, ASICs, FPGAs, or discrete logic devices. Controller 822 may also include one or more memories 826, such as random access memory, read-only memory, hard disk drives, flash memory, optical disks, or other suitable electrically or non-electrically dependent storage devices. Controller 822 may further include one or more interfaces 828 supporting communication with other systems or devices, such as network interface cards or wireless transceivers that facilitate communication via wired or wireless networks or direct connections.

[0067] Figures 8C and 8D illustrate example layouts 850 and 870 of architecture 800. In Figure 8C, a first integrated circuit chip 852 may include CMOS components of architecture 800, and a second integrated circuit chip 854 may include other components of architecture 800. In some embodiments, integrated circuit chip 852 may be silicon-based, and integrated circuit chip 854 may be GaN-based. A multilayer high-frequency laminate 856 may be used to couple integrated circuit chips 852 and 854 and allow signal transmission between integrated circuit chips 852 and 854.

[0068] In FIG. 8D, the first integrated circuit chip 872 may include CMOS components of architecture 800, and the second integrated circuit chip 874 may include other components of architecture 800. In some embodiments, the integrated circuit chip 872 may be silicon-based, and the integrated circuit chip 874 may be a monolithic microwave integrated circuit (MMIC) based on benzocyclobutene (BCB). An insert 876 (such as a printed circuit board) may be used to couple the integrated circuit chips 872 and 874 and allow signal transmission between the integrated circuit chips 872 and 874. One or more I / O lines 878 may be used to provide signals to or receive signals from the integrated circuit chip 874.

[0069] Although Figures 8A to 8D illustrate one instance of an architecture 800 supporting a non-reciprocal cyclic transceiver, various modifications can be made to Figures 8A to 8D. For example, any other suitable architecture may use one or more non-reciprocal cyclic circuits to perform one or more desired functions. Furthermore, any other suitable layout may be used to implement architecture 800. Additionally, the various components in each figure may be combined, further subdivided, copied, omitted, or reconfigured, and additional components may be added as needed.

[0070] Figure 9 illustrates an example method 900 for using a reconfigurable broadband high-frequency circuit with a non-reciprocal cyclic converter, according to the present disclosure. For ease of explanation, method 900 is described as being performed using the circuit 100 of Figure 1, which can be used in larger systems such as architecture 800 of Figure 8A. However, method 900 can be performed using any suitable means and in any suitable system.

[0071] As shown in FIG9, at step 902, one or more reflective circuit elements to be used to modify the RF input signal are identified (if present). For example, this may include the control system 814, controller 822, or other components identifying one or more reflective circuit elements 104a to 104n to be used to modify the RF input signal 108. This may be done in various ways depending on the implementation. For example, one sequence of reflective circuit elements 104a to 104n may be used in series during a sweep of the frequency range, or the modification provided by reflective circuit elements 104a to 104n may be selected to provide the desired modification from one or more of the reflective circuit elements 104a to 104n. It should be noted that the indication "if present" here is because in some situations isolation functionality may be required, rather than involving another signal processing operation using one or more reflective circuit elements 104a to 104n.

[0072] At step 904, control signals are generated based on one or more identified reflective circuit elements (if present). This may include, for example, a control system 814, a controller 822, or other components controlling a pulse source 816 to generate continuous pulses in the control signals provided to the switch of at least one non-reciprocal circulator 102. The pulse control RF input signal 108 in these control signals will pass through one, some, all, or none of the reflective circuit elements 104a to 104n (depending on specific requirements).

[0073] At step 908, an RF input signal is received at a non-reciprocal circulator, and at step 910, one or more identified reflective circuit elements (if present) are optionally used to modify the RF input signal. This may include, for example, the non-reciprocal circulator 102 passing the RF input signal 108 to one of the reflective circuit elements 104a to 104n, and receiving the modified RF signal from that reflective circuit element. This may also include the non-reciprocal circulator 102 passing the modified RF signal to another of the reflective circuit elements 104a to 104n, and receiving the modified RF signal from that reflective circuit element. This may be done any number of times based on the number of identified reflective circuit elements 104a to 104n used to modify the RF input signal 108. If an isolator function is being implemented, the RF input signal 108 may not be provided to the reflective circuit element. At step 910, an RF output signal is provided from the non-reciprocal circulator. This may include, for example, a non-reciprocal cyclic 102 outputting an RF output signal 110, which represents an RF input signal 108 modified by the non-reciprocal cyclic 102 and, where appropriate, by at least one of the reflective circuit elements 104a to 104n.

[0074] Although Figure 9 illustrates one example of a method 900 for using a reconfigurable broadband high-frequency circuit with a non-reciprocal cyclic converter, various modifications can be made to Figure 9. For example, although shown as a series of steps, the various steps in Figure 9 can overlap, be performed in parallel, be performed in different orders, or occur any number of times. As a specific example, the reflective circuit elements 104a to 104n identified and used during signal modification can change over time (such as during frequency sweeps or between intermittent isolator operations).

[0075] It should be noted that although different circuits have been described above, combinations of features from different circuits may be used together as needed. For example, a circuit may include at least one non-reciprocal cyclic element 102 and a plurality of reflective circuit elements 104a to 104n, wherein the reflective circuit elements 104a to 104n include phase delay elements, attenuation elements, and / or other types of reflective circuit elements (or any combination thereof). Although a particular example of this situation is shown in the architecture 800 of Figure 8A, due to its inclusion of both a phase shifter and an attenuator, other combinations of reflective circuit elements may be used in any given circuit or architecture. As another example, one or more clock sources 816 can be used in any of circuits 100, 200, 300, 400, 500, and 700 to generate control signals for non-reciprocal cyclic circuits 102, 102a to 102b, and 702, and controller 822 can be used in any of circuits 100, 200, 300, 400, 500, and 700 to adjust the control signals for non-reciprocal cyclic circuits 102, 102a to 102b, and 702. Therefore, any feature shown in one or more of the figures described above can be used as needed in the circuit of another figure described above.

[0076] In some embodiments, the various functions described in this patent document are implemented or supported by a computer program, which is formed by computer-readable code and implemented in a computer-readable medium. The phrase "computer-readable code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of media accessible by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive (HDD), optical disc (CD), digital video disc (DVD), or any other type of memory. "Non-transitory" computer-readable media does not include wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable media includes media in which data can be permanently stored and media in which data can be stored and subsequently overwritten, such as rewritable optical discs or erasable storage devices.

[0077] It may be advantageous to define certain words and phrases used throughout this patent document. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, procedures, functions, objects, classes, examples, related data, or portions thereof that are applicable to implementation in suitable computer code (including source code, object code, or executable code). The term "communication" and its derivatives cover both direct and indirect communication. The terms "comprising" and "including" and their derivatives mean unrestricted inclusion. The term "or" is inclusive, meaning and / or. The phrase "associated with" and its derivatives may mean including, being contained in, interconnected with, containing, being contained within, connected to or connected with, coupled to or coupled with, able to communicate with, cooperate with, interleaved, juxtaposed, proximate, combined with or combined with, having, having properties, having a relationship with or having a relationship with, or similar to. When used with a list of items, the phrase "at least one of" means that different combinations of one or more of the listed items may be used, and only one item from the list may be required. For example, "at least one of A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A, B, and C.

[0078] The descriptions in this disclosure should not be construed as implying that any specific element, step, or function must be included as a fundamental or critical element within the scope of the claim. The scope of the patented subject matter is defined solely by the permitted scope of the application. Furthermore, unless the specific claim explicitly uses the exact words “for a manner of…” or “for a step of…” followed by a participle identifying the function, none of the claims references 35 USC § 112(f) to any of the appended claims or elements of the claim. The use of terms such as (but not limited to) “mechanism,” “module,” “device,” “unit,” “component,” “element,” “part,” “equipment,” “machine,” “system,” “processor,” or “controller” in the claim is to be understood and intended to refer to a further modification or enhancement of a structure known to those skilled in the art, such as the features of the claims themselves, and is not intended to reference 35 USC § 112(f).

[0079] Although certain embodiments and generally associated methods have been described in this disclosure, modifications and arrangements of these embodiments and methods will be apparent to those skilled in the art. Therefore, the above description of exemplary embodiments does not define or limit this disclosure. As defined in the following claims, other changes, substitutions, and alterations are possible without departing from the spirit and scope of this disclosure. [Simplified Explanation of the Diagram]

[0012] To gain a more complete understanding of this disclosure, the following description is now taken in conjunction with the accompanying drawings, in which:

[0013] Figure 1 illustrates a circuit based on a non-reciprocal cyclic circuit according to an example of the present disclosure;

[0014] Figure 2 illustrates an example of a circuit based on a non-reciprocal cyclic converter that supports the function of a balanced-to-unbalanced converter according to the present disclosure;

[0015] Figure 3 illustrates an example of a non-reciprocal cyclic circuit based on a broadband reconfigurable phase shift according to the present disclosure;

[0016] Figure 4 illustrates another example of a circuit based on a non-reciprocal cyclic circuit that supports broadband reconfigurable phase shift according to the present disclosure;

[0017] Figure 5 illustrates a specific example implementation of a non-reciprocal cyclic circuit supporting broadband reconfigurable phase shift according to the present disclosure;

[0018] Figures 6A and 6B illustrate an example of a non-reciprocal looper and its operation according to the present disclosure;

[0019] Figure 7 illustrates an example of a circuit based on a non-reciprocal cyclic circuit that supports isolator functionality according to this disclosure;

[0020] Figures 8A to 8D illustrate an instance architecture supporting a non-reciprocal cyclic transceiver based on this disclosure; and

[0021] Figure 9 illustrates an example method for using a reconfigurable broadband high-frequency circuit with a non-reciprocal cyclic converter, according to the present disclosure.

Claims

1. A communication system comprising: at least one non-reciprocal circulator; and one or more reflective circuit elements, each reflective circuit element being configured to receive a radio frequency (RF) signal from the at least one non-reciprocal circulator and to provide a modified RF signal to the at least one non-reciprocal circulator; wherein each non-reciprocal circulator comprises: (1) a plurality of switches coupled to a common node of the non-reciprocal circulator, and (2) at least one energy storage device coupled to the common node of the non-reciprocal circulator.

2. The communication system as described in request item 1, wherein: The one or more reflective circuit elements include phase-change reflectors configured to modify one phase of the RF signal; and the at least one non-reciprocal cyclic device and the phase-change reflectors form a broadband reconfigurable phase shifter.

3. The communication system as described in request item 2, wherein: These phase change reflectors include multiple reference phase change reflectors and multiple phase shift reflectors; and different pairs of a reference phase change reflector and a phase shift reflector are combined to provide different amounts of phase shift.

4. The communication system as described in request item 1, wherein: The at least one non-reciprocal cyclic includes a first non-reciprocal cyclic and a second non-reciprocal cyclic; the one or more reflective circuit elements include a first reflective phase delay element coupled to one of the first non-reciprocal cyclic and a second reflective phase delay element coupled to one of the second non-reciprocal cyclic; and the non-reciprocal cyclic and the reflective phase delay elements form a balanced-to-unbalanced converter.

5. A communication system comprising: at least one non-reciprocal cyclic converter; and one or more reflective circuit elements, each reflective circuit element being configured to receive a radio frequency (RF) signal from the at least one non-reciprocal cyclic converter and provide a modified RF signal to the at least one non-reciprocal cyclic converter; wherein each non-reciprocal cyclic converter comprises a plurality of switches; and wherein the switches of each non-reciprocal cyclic converter are configured to be controlled using non-overlapping pulses in respective control signals.

6. The communication system of claim 5, wherein the system can reconfigure based on changing one sequence of the non-overlapping pulses in the control signals.

7. The communication system as described in request item 1, wherein: The one or more reflective circuit elements form multiple circuit branches; the at least one non-reciprocal cyclic unit is configured to receive an RF input signal and provide an RF output signal, the RF output signal representing the RF input signal as modified by at least one of the one or more reflective circuit elements; and at least one of the circuit branches is configured to selectively generate the RF output signal.

8. The communication system of claim 1, wherein the at least one non-reciprocal cyclic device comprises: a first group of one or more non-reciprocal cyclic devices coupled to a first type of reflective circuit element; and a second group of one or more non-reciprocal cyclic devices coupled to a second type of reflective circuit element; and wherein the non-reciprocal cyclic devices in the first group and the second group are coupled together in series.

9. A communication system comprising: at least one non-reciprocal cyclic converter; and one or more reflective circuit elements, each reflective circuit element being configured to receive a radio frequency (RF) signal from the at least one non-reciprocal cyclic converter and provide a modified RF signal to the at least one non-reciprocal cyclic converter; wherein each non-reciprocal cyclic converter may be configured to function as an isolator, wherein the non-reciprocal cyclic converter is not electrically coupled to any reflective circuit element during operation as the isolator.

10. A method for signal modification, comprising: receiving a radio frequency (RF) input signal using at least one non-reciprocal circulator; and generating an RF output signal using at least one of one or more reflective circuit elements, each reflective circuit element being configured to receive an RF signal from the at least one non-reciprocal circulator and provide a modified RF signal to the at least one non-reciprocal circulator; wherein the RF output signal represents the RF input signal as modified by the at least one of the one or more reflective circuit elements; and wherein each non-reciprocal circulator comprises: (1) a plurality of switches coupled to a common node of the non-reciprocal circulator, and (2) at least one energy storage device coupled to the common node of the non-reciprocal circulator.

11. As in request item 10, wherein: The one or more reflective circuit elements include phase-change reflectors configured to modify one phase of the RF signal; and the at least one non-reciprocal cyclic device and the phase-change reflectors form a broadband reconfigurable phase shifter.

12. As in request item 11, wherein: These phase change reflectors include multiple reference phase change reflectors and multiple phase shift reflectors; and different pairs of a reference phase change reflector and a phase shift reflector are combined to provide different amounts of phase shift.

13. As in request item 10, wherein: The at least one non-reciprocal cyclic includes a first non-reciprocal cyclic and a second non-reciprocal cyclic; the one or more reflective circuit elements include a first reflective phase delay element coupled to one of the first non-reciprocal cyclic and a second reflective phase delay element coupled to one of the second non-reciprocal cyclic; and the non-reciprocal cyclic and the reflective phase delay elements form a balanced-to-unbalanced converter.

14. As in request item 10, wherein: Each non-reciprocal cyclic switch is controlled using non-overlapping pulses in its respective control signal.

15. The method of claim 14, further comprising: reconfiguring a system including the at least one non-reciprocal cyclic circuit and the one or more reflective circuit elements by changing a sequence of the non-overlapping pulses in the control signals.

16. As in request item 10, wherein: The one or more reflective circuit elements form multiple circuit branches; and one or more of these circuit branches are selectively used to generate the RF output signal.

17. The method of claim 10, further comprising: assembling the at least one non-reciprocal cyclic device to serve as an isolator, wherein each non-reciprocal cyclic device serving as an isolator is not electrically coupled to any reflective circuit element during operation as the isolator.

18. A non-transitory computer-readable medium containing, when executed, instructions to cause at least one controller to: reconfigure a system comprising at least one non-reciprocal cyclic device and a plurality of reflective circuit elements, each reflective circuit element being configured to receive a radio frequency (RF) signal from the at least one non-reciprocal cyclic device and to provide a modified RF signal to the at least one non-reciprocal cyclic device; wherein the instructions to cause the at least one controller to reconfigure the system include instructions to: cause the at least one controller to change a sequence of non-overlapping pulses in control signals provided to a plurality of switches of each non-reciprocal cyclic device to selectively control which of the reflective circuit elements is electrically coupled to the at least one non-reciprocal cyclic device.

19. The non-transitory computer-readable medium of claim 18, wherein the instructions for causing the at least one controller to change the sequence of non-overlapping pulses in the control signals provided to the switches of each non-reciprocal circulator comprise: instructions that cause the at least one controller to change the sequence of non-overlapping pulses in the control signals provided to the switches of each non-reciprocal circulator in order to change which of the reflective circuit elements is electrically coupled to the at least one non-reciprocal circulator during operation.

20. Non-transitory computer-readable media as in claim 18, wherein: The reflective circuit elements form multiple circuit branches; and the instructions that cause the at least one controller to change the sequence of non-overlapping pulses in the control signals provided to the switches of each non-reciprocal cyclic circuit include: instructions that cause the at least one controller to change the sequence of non-overlapping pulses in the control signals provided to the switches of each non-reciprocal cyclic circuit in order to change which of the circuit branches is used to modify an RF input signal and generate an RF output signal.

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