Systems and methods for active s11 detection in phased array transceivers

Abstract

Apparatuses and methods are provided for detection of active return loss of an antenna element of a plurality of antenna elements of a phased array antenna. An example apparatus can convert a voltage difference at an input of a power amplifier (PA) to a first current. The apparatus can convert a coupled voltage corresponding to a signal transmitted from the PA to a respective antenna element to a second current. The apparatus can convert a reflected voltage corresponding to a signal reflected from the respective antenna element to a third current. The apparatus can convert the first current, the second current, and the third current to an output voltage at an output of a generator. The apparatus can also have a controller that can adaptively generate a codebook for transmission based on the output voltage.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to wireless communications. More specifically, the present disclosure relates to phased array antenna management for millimeter wave (MMW) transmissions. BACKGROUND

[0002] Wireless communications systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Wireless communications systems can employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA), and time division synchronous code division multiple access (TD-SCDMA) systems.

[0003] Such multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. One example telecommunication standard is 5G New Radio (NR). 5G NR can enable broadband wireless capabilities for a variety of wireless devices, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz above) with extreme mobile broadband data rates (e.g., 20 Gbps), millimeter wave (mmW) targeting high carrier frequency (e.g., 60 GHz) with

[0004] Due to the relatively high attenuation of MMW transmissions, multiple antenna arrays can be used to improve the accuracy and gain of receiving transmissions. Some of the antenna arrays can be multiple-input multiple-output (MIMO) antenna arrays or phased array systems

[0005] Implementations of 5G NR systems can include phased array antennas in mobile wireless devices, such as user equipment (UE), and larger fixed systems, such as customer premises equipment (CPE), enabling directional transmission of signals. Some of the phased array antennas have a large number of elements. In large arrays, the coupling between the antenna elements can be problematic. SUMMARY

[0006] The following brief summary provides an overview of one or more aspects. The summary is not an extensive overview of all contemplated aspects and is neither intended to identify key or essential

[0007] One aspect of the disclosure provides an apparatus for detection of active return loss of an antenna element of a plurality of antenna elements of a phased array antenna. The apparatus can have a power amplifier (PA) having an output coupled to the antenna element of the plurality of elements via a transmission line. The apparatus can have a first current sensor coupled to an input of the PA. The first current sensor can convert a voltage at the input to a first current. The apparatus can have a second current sensor in communication with the transmission line. The second current sensor can convert a coupled voltage corresponding to a signal transmitted from the PA to the antenna element to a second current. The second current sensor can convert a reflected voltage reflected from the antenna element to a third current. The apparatus can have a voltage generator coupled to the first current sensor and the second current sensor and configured to convert the first current, the second current, and the third current to an output voltage at an output of the generator.

[0008] Another aspect of the disclosure provides an apparatus for detection of active return loss of each antenna element of a plurality of antenna elements of a phased array antenna. The apparatus can have means for amplifying coupled to each antenna element of the plurality of elements via a transmission line. The apparatus can have first sensing means for sensing a voltage at an input of the means for amplifying. The first sensing means can convert the voltage at the input to a first current. The apparatus can have second sensing means for sensing a voltage on the transmission line. The second sensing means can have means for converting a coupled voltage corresponding to a signal transmitted from the means for amplifying to the respective antenna element to a second current. The apparatus can have means for converting a reflected voltage reflected from the respective antenna element to a third current. The apparatus can have means for generating a voltage based on the first current, the second current, and the third current.

[0009] Another aspect of the disclosure provides a three-mode power detector for detecting an active return loss of each of a plurality of antenna elements of a phased array antenna. The three-mode power detector can have a differential RMS current sensor configured to convert a first voltage difference at an input of a power amplifier (PA) to a first current, the PA coupled to a respective antenna element of the plurality of antenna elements via a transmission line. The three-mode power detector can have a RMS current sensor. The RMS current sensor can convert a coupled voltage corresponding to a signal transmitted from the PA to the respective antenna element to a second current. The RMS current sensor can convert a reflected voltage corresponding to a signal reflected from the respective antenna element to a third current. The three-mode power detector can have a voltage generator coupled to the DRCS and the RCS and configured to convert the first current, the second current, and the third current to an output voltage at a generator output.

[0010] Another aspect of the disclosure provides a method for detecting an active return loss of each of a plurality of antenna elements of a phased array antenna. The method can include converting a voltage to a first current, the voltage sensed by a first current sensor coupled to an input of a power amplifier (PA), where the PA has an output coupled to an antenna element of the plurality of elements via a transmission line. The method further includes converting, by a second current sensor in communication with the transmission line, a coupled voltage corresponding to a signal transmitted from the PA to the antenna element to a second current; and converting a reflected voltage reflected from the antenna element to a third current. The method further includes converting, by a voltage generator coupled to the first current sensor and the second current sensor, the first current, the second current, and the third current to an output voltage at a generator output.

[0011] Other features and advantages will be apparent to those of ordinary skill in the art upon reviewing the following description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0012] Details of the structure and operation of embodiments of the present disclosure can be gleaned in part by studying the drawings, in which like reference numerals refer to like parts, and in which:

[0013] Figure 1 is a pictorial representation of a wireless communication system;

[0014] Figure 2 is a functional block diagram of a communication device for use with the system of Figure 1

[0015] Figure 3 is a schematic diagram of portions of the communication device of Figure 2

[0016] Figure 4 ​​is a graphical representation of an embodiment of an antenna system of Figure 2 and Figure 3 is a graphical representation of an embodiment of an antenna system of

[0017] Figure 5 is a schematic diagram of an embodiment of a coupler of Figure 3

[0018] Figure 6 is a schematic diagram of an embodiment of a detector of Figure 3

[0019] Figure 7 is a schematic diagram of a second state of a detector of Figure 6

[0020] Figure 8 is a schematic diagram of a third state of a detector of Figure 6

[0021] Figure 9 is a flowchart of an embodiment of a method for detecting and managing active s11 in a phased array antenna according to the present disclosure. DETAILED DESCRIPTION

[0022] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0023] The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0024] ​​​​Various next generation wireless technologies in millimeter wave (mmW) bands (e.g., 5G, certain WLAN standards) implement phased array transceivers. As used herein, phased array generally refers to an array that is electronically scanned, such as a computer-controlled array of antennas that forms one or more radio wave beams that can be electronically steered to point in different directions without moving the antennas. In an array antenna (e.g., a phased array), radio frequency signals from a transmitter are fed to individual antennas with the correct phase relationship so that radio waves from the separate antennas add together to increase the radiation in the desired direction, while cancelling to suppress radiation in undesired directions. Because the array includes multiple antennas to achieve high antenna array gain, phased arrays become more practical with an increase in frequency and a decrease in individual antenna element size.

[0025] In phased array transmitters, particularly large phased array transmitters, multiple antenna elements can couple, causing a large amount of power to be reflected back to the power amplifier (PA) that powers a given antenna element. The reflected power can be described with a reflection coefficient (also referred to as s11). The reflection coefficient also forms the basis of the voltage standing wave ratio (VSWR). Over time, large s11 variations can affect PA reliability, eventually leading to PA failure and degradation of antenna array performance. For example, active s11 can cause large output voltage fluctuations in one or more elements of the phased array, or cause redundant power consumption, canceling the signal at the coupled element. This further compromises the overall effectively isotropically radiated power (EIRP).

[0026] Certain aspects of the present disclosure aim to detect antenna elements experiencing high s11 and shut them down to improve long-term reliability and to improve power consumption. Certain disclosed systems and methods provide active VSWR detection and corresponding system control for large phased arrays. Certain disclosed systems can provide improved VSWR measurement accuracy without high directional couplers. Some such systems can be implemented in a relatively small area, which can reduce the impact on the already small space in 5G mmW phased arrays.

[0027] Figure 1is a pictorial representation of a wireless communication system. The wireless communication system (system) 100 can include a wireless device 110. The wireless device 110 can have a (multi-band) millimeter wave (mmW) transceiver. The system 100 can be a 5G system, a Long Term Evolution (LTE) system, a Code Division Multiple Access (CDMA) system, a Global System for Mobile Communications (GSM) system, one of various members of the wireless protocol family IEEE 802.XX (e.g., Wi-Fi or mmW Wi-Fi), a Wireless Local Area Network (WLAN) system, a millimeter wave (mmW) technology, or some other wireless system. A CDMA system can implement Wideband CDMA (WCDMA), Time Division Synchronous CDMA (TD-SCDMA), CDMA2000, or some other version of CDMA. In a millimeter wave (mmW) system, multiple antennas are used for beamforming (e.g., in the range of 30 GHz, 60 GHz, etc.). The system 100 can also include a first base station (BS) 120 and a second BS 130 in communication with the wireless device 110. In general, the system 100 can include any number of base stations and any number of network entities. The system 100 is merely one example. Other examples, as described in further detail below, can have substantially different architectures and / or configurations. Figure 1 Any or all of the devices described can implement a multi-element antenna array or a phased array antenna.

[0028] The wireless device 110 can be referred to as a user equipment (UE), a mobile station, a terminal, an access terminal, a subscriber unit, a station, etc. The wireless device 110 can also be a cellular phone, a smartphone, a tablet, a wireless modem, a personal digital assistant (PDA), a handheld device, a laptop computer, a smartbook, a netbook, a cordless phone, a wireless local loop (WLL) station, an Internet of Things (IoT) device, a device in a vehicle, a medical device, a Bluetooth device, etc. The wireless device 110 can be capable of communicating with the first BS 120 and the second BS 130. The wireless device 110 can also be capable of receiving signals from a broadcast station (e.g., the broadcast station 134), from one or more satellites 150 in one or more global navigation satellite systems (GNSS), etc. In addition, the wireless device 110 can be capable of communicating directly with another wireless device (not shown) in addition to or instead of communicating through one of the illustrated networks. The wireless device 110 can support one or more radio technologies for wireless communication such as 5G, LTE, CDMA2000, WCDMA, TD-SCDMA, GSM, 802.11, etc.

[0029] Figure 2 is a functional block diagram of a communication device for use with the system of Figure 1 is a functional block diagram of a communication device for use with the system of

[0030] The device 200 can include one or more processors or processor cores (processors) 204. The processors 204 can control operation of the device 200. The processors 204 can also be referred to herein as central processing units (CPUs). The processors 204 can include or be components of a processing system or controller implemented with one or more processors 204. The one or more processors can be implemented with any combination of general-purpose microprocessors, microcontrollers, neural processing units (NPUs), one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), controllers, state machines, gated logic, discrete hardware components, or any other suitable entities that can perform calculations or other manipulations of information. In some embodiments, the processors 204 can also perform quantum computing functions. In some embodiments, the processors 204 include a modem and / or an application processor.

[0031] The device 200 can also have a memory 206 coupled to the processors 204. The memory 206 can include both read only memory (ROM) and random access memory (RAM). The memory 206 can provide instructions and data to the processors 204. The memory 206 can store program codes, instructions, and data for the processors 204. The memory 206 can also store codebooks (e.g., adaptive codebooks) for storing beamforming codes for a phased array antenna. Each codebook can contain a (beamforming) code that represents a weighting or phase shift that can be applied to different versions of a signal(s) transmitted from a phased array to properly form a beam. This will be described in more detail in connection with FIG. 3. Figure 3

[0032] At least a portion of the memory 206 can also include non-volatile random access memory (NVRAM). The processors 204 can perform logical and arithmetic operations based on program instructions stored within the memory 206. The instructions in the memory 206 can be executable to implement the methods described herein. The processors 204 and the memory 206 can also include machine-readable media for storing software. Software shall be construed broadly to mean any type of instructions, whether referred to as software, firmware, middleware, microcode, hardware description language, machine learning, artificial intelligence (AI), or otherwise. The instructions can include code (e.g., in source code format, binary code format, executable code format, or any other suitable format of code). The instructions, when executed by one or more processors, enable the processing system to perform a variety of functions as described herein.

[0033] ​The device 200 can also include a transmitter system 210 and / or a receiver system 212 to allow transmission and reception of data between the device 200 and remote locations. The transmitter system 210 and receiver system 212 can be combined into a transceiver system 214. References herein to the transceiver system 214 can be considered as references to either the transmitter system 210 and receiver system 212 as appropriate, with the necessary or compatible characteristics and functions being imparted as appropriate. The device 200 can also have an antenna system 216 communicatively coupled to the transceiver system 214. The antenna system 216 can have multiple individual antenna elements Figure 4 ), arranged, for example, in a multi-element patch antenna or other type of phased array, to enable beamforming.

[0034] The transceiver system 214 can include multiple transmitters (e.g., in the transmitter system 210), multiple receivers (e.g., in the receiver system 212), multiple transceivers, and / or multiple antennas, as necessary in accordance with the requirements of various communication standards.

[0035] The transmitter system 210 (e.g., or the transceiver system 214) can be configured to wirelessly transmit packets having different packet types or functions. For example, the transmitter system 210 can be configured to transmit different types of packets generated by the processor 204. For example, the processor 204 can be configured to determine a type of a packet and to process the packet and / or fields of the packet accordingly.

[0036] The receiver system 212 (e.g., or the transceiver system 214) can be configured to wirelessly receive packets having different packet types or other information. In some examples, the processor 204 and / or the receiver system 212 can be configured to detect a type of a packet used and to process the packet accordingly.

[0037] Figure 3 is Figure 2 a functional block diagram of portions of a communication device of

[0038] The transceiver system 214 can have multiple transmitters and multiple receivers coupled to the antenna system 216 to support multiple frequency bands, multiple radio technologies, carrier aggregation, transmit / receive diversity, multiple-input multiple-output (MIMO) transmission from multiple transmit antennas to multiple receive antennas, etc.

[0039] The transceiver system 214 can also have multiple receive chains 330. For simplicity, only a low noise amplifier 332 is shown in the receive chains 330. The receive chains 330 can receive signals / transmissions from the antenna system 216 for processing.

[0040] The processor 204 can also perform processing for data received via a receiver of the receiver system 212 and data transmitted via a transmitter of the transmit system 210. The processor 204 can control operation of various circuits within the transceiver system 214.

[0041] The transmit chain 310a can have a phase shifter 312a. The phase shifter 312a can cooperate with other phase shifters 312 (e.g., 312a-312n) to adjust the phase of a transmit signal to achieve proper beamforming at different antenna elements of an antenna array.

[0042] The transmit chain 310a can have a power amplifier 316a coupled to the phase shifter 312a via a driver amplifier (DA) 315a. The transmit chain 310n can have a power amplifier 316n coupled to the phase shifter 312n via a DA 315n. In the illustrated embodiment, the DAs 315a-315n can be used to amplify a small signal from the phase shifters (312a-n) and provide an appropriate voltage swing at the input of the power amplifiers (316a-n). In the illustrated embodiment, the DAs 315a-315n are also configured to output differential signals (and can be configured to convert single-ended signals to differential signals). In other embodiments, the DAs 315a-n are configured to output single-ended signals or are omitted. The power amplifier 316a can apply gain to a transmit signal, e.g., provided by the processor 204. The output of the power amplifier 316 can be coupled to one or more antenna elements 322 (labeled 322a-322n) of the antenna system 216. In some implementations, the antenna system 216 can include a phased array antenna or a patch antenna array with antenna elements 1-n. The antenna system 216 can have a plurality of antenna elements 322 arranged to produce a desired beamforming pattern. In some examples, the antenna elements 322 can be arranged in a square (e.g., 5 by 5), a rectangle (e.g., 2 by 6), a straight or linear pattern, or other arrangement as desired. For example, a mobile phone can have a smaller 1 by 4 or 2 by 2 or 3 by 4 patch antenna, while a larger CPE antenna can have a 5 by 5 antenna, an 8 by 8 antenna, or more. The antenna elements 322 are primarily described in connection with the transmit chains 310, however the antenna system 216 and antenna elements 322 are also coupled to the receive chains 330 (e.g., receive chains 330a-330n) for receive operations at the antenna system 216.

[0043] For data transmission, processor 204 processes (e.g., encodes and modulates) the data to be transmitted and provides an analog output signal to the selected transmitter (e.g., the transmitter of transmitter chain 310a). Within transmitter chain 310a, various transmitting circuits can amplify, filter, and up-convert the analog output signal from baseband to RF and provide a modulated RF signal. Transmitter chain 310a may include amplifiers, filters, mixers, matching circuits, oscillators, local oscillator (LO) generators, PLLs, etc. Power amplifier 316a can receive and amplify the modulated RF signal and provide a transmitted RF signal with an appropriate output power level. The transmitted RF signal is routed through antenna system 216 via antenna 322. Each of the other transmitter chains 310 (e.g., to transmitter chain 310n) can operate in a similar manner to transmitter chain 310a.

[0044] A codebook, or an adaptive codebook as used herein, can store beamforming weights (e.g., power and / or phase) for each antenna element 322 of the phased array antenna system 216. Beamforming codes can induce various beamforming patterns that guide the energy of the entire antenna system 216 based on the phase shift of the individual antenna element 322. When the codebook provides zero-power to the antenna element 322, the antenna element can be considered disconnected (e.g., deactivated or otherwise inactive or not added to beamforming). A beamforming lookup table can be provided for each beamforming angle based on the codebook. The beamforming lookup table can provide beamforming codes for the antenna element 322 to appropriately form a beam at a given beamforming angle. For example, a lookup table for a given beamforming angle provides beamforming weights (e.g., power and / or phase) for each antenna element 322 to form a beam at a given angle. That is, the codebook can provide beamforming codes on an antenna element basis, while the beamforming lookup table provides beamforming codes on a beamforming angle basis.

[0045] exist Figure 3 In an exemplary embodiment, the transceiver system 214 may further include Figure 3 Other circuitry not shown, such as filters, matching circuits, etc., may be included. All or part of the transceiver system 214 may be implemented on one or more analog integrated circuits (ICs), RF ICs, mixed-signal ICs, etc. In some embodiments, Figure 3 All components of the transceiver system 214 and all antennas 322 (e.g., for a single phased array) shown are included in the module. In other embodiments, one or more components of the transceiver system 214 (e.g., phase shifters 312) are integrated with... Figure 3 The remaining components of the transceiver 214 shown are implemented on different ICs or in different modules / packages.

[0046] In some embodiments, LNA 332 and PA 316 are Figure 2 example embodiments of LNAs and PAs of exemplary transceiver system 214, such as when transceiver system 214 is configured to implement a phased array antenna system. Such phased array systems (e.g., antenna system 216) can be used for higher frequency communications, such as 30 GHz and 60 GHz, to realize the benefits of beamforming.

[0047] Transmit chain 310a can also include a power and impedance detector (detector) 350 (labeled 350a-350n, and shown in dashed lines). Detector 350 can also be referred to herein as a three-mode power detector. For example, detector 350 can measure the voltage or input power at the input at PA 316 (Pdet_PA), the output transmitter power (Pdet_MAIN), and the reflected power from the antenna load (Pdet_RVS). These three measurements can be used to adapt the codebook to a given beamforming code set. For example, if the reflected power or sll is very high for a given beamforming code set, the disclosed methods can determine when certain antenna elements 322 should be disabled based on sll.

[0048] For example, detector 350a can be inductively coupled to transmission line 318a between PA 316a and antenna system 216. Detector 350 can be coupled to transmission line 318a through coupler 320a. In some embodiments, coupler 320a can be a compact or low-directivity coupler. A compact coupler can be advantageous because the relative size requirements are small. Coupler 320a can be, for example, a single coupled transformer. Each transmit chain 310 implements such a coupler 320 (e.g., couplers 320a-320n), and it can be particularly advantageous to implement such couplers 320 with small size for larger phased arrays. In some embodiments, couplers 320 can be implemented as coupled line couplers, transformer-based couplers, Bethe hole couplers, multi-hole couplers, two-way couplers, or other applicable couplers. In some embodiments, transformer-based couplers can generally be compact, and can be used for all couplers 320. However, not all couplers 320 need to be the same type of coupler. In some embodiments, one or more of couplers 320 (e.g., coupler 320a) are configured as a first type (e.g., transformer-based couplers), and one or more other couplers (e.g., coupler 320n) are configured as a second type (e.g., Bethe hole couplers).

[0049] The detector 350 can include current sensors (CS) 352 (labeled CS 352a-352n). The CS 352 can sense the voltage at the input of the PA 316 (which is proportional to the input power for a given constant impedance) and convert that voltage to a current. In this example, the PA 316 is a differential PA, and thus the CS 352 can be a differential current sensor configured to sense the voltage across the differential input of the PA 316 and output a current. However, in other examples, the input of the PA 316 and the CS 352 can be single-ended. Thus, the CS 352a can provide a current corresponding to the input voltage of the PA 316a (Pdet PA).

[0050] The coupler 320a disposed between the PA 316a and the antenna system 216 can allow for measurement of both the transmitted power (at port C) and the reflected power (at port D) from the antenna system 216. The coupler 320a can provide inductive connections to various circuitry to measure the transmitted power and the reflected power on the transmission line 318a Figure 5 ).

[0051] The detector 350a can also have a current sensor (CS) 354a (labeled CS 354n in the detector 350n). The CS 354a can sense the signals or voltages of both the transmitted voltage at port C (e.g., on the transmission line 318a) (Pdet MAIN) and the reflected voltage at port D (Pdet RVS) and convert them to a current. The voltages at port C and port D can represent the transmitted signal and the portion of the transmitted signal reflected from the antenna system 216, respectively. For example, the ratio of the voltage at port C to the voltage at port D can also be referred to as the voltage standing wave ratio (VSWR).

[0052] On the other hand, the standing wave ratio (SWR) is a measure of the impedance matching of the load to the characteristic impedance of the transmission line 318a. Impedance mismatch results in these standing waves along the transmission line 318a, and the SWR is defined as the ratio of the amplitude (maximum) of the partial standing wave at the antinode to the amplitude (minimum) along the transmission line at the node. These impedances are described below in relation to the SWR. Figure 5When the VSWR fluctuates based on transmission, certain transmit chains 310 can have very high levels of power reflected from the corresponding antenna elements 322. Over time, the high levels of reflected power can damage the PAs 316. Thus, it can be advantageous to disable or otherwise shut down a particular transmit chain 310 or antenna element 322 when the associated reflected power or VSWR reaches or exceeds a threshold. These details can be stored in an adaptive codebook, so certain antenna elements 322 can be disabled for beamforming patterns that have known high s11.

[0053] The CS 354a can generate a current corresponding to the voltage sensed or otherwise received at each of port C and port D. The reflected power / voltage sensed at port D, and thus the current generated at the CS 354a, can vary with the coupling between the antenna elements 322 of the antenna system 216.

[0054] The detector 350 can have a shared voltage generator 358a (labeled shared voltage generator 358n in the detector 350n) coupled to the CS 352a and the CS 354a. In Figure 3 In the illustrated embodiment, the voltage generator 358a can generate a voltage based on the current received from the CS 352a and the CS 354a. Fluctuations in the generated voltage can represent changes in the ratio between the input power sensed at the CS 352a and the VSWR changes at the CS 354a. Changes in the ratio between the input power sensed at the CS 352a and the VSWR changes at the CS 354a can be determined by the controller 360 based on the generated voltage (as described below). In some embodiments, a respective voltage-to-current converter is coupled to each CS 352, 354 (e.g., as opposed to the shared voltage generator being implemented), and the outputs of the respective voltage-to-current converters are provided to the controller 360 individually, or the outputs are coupled to a common path that is coupled to the controller 360. In other embodiments, in place of the shared voltage generator 358 (and / or portions of the controller 360), a comparator or other circuitry configured to sense changes between the input power and the VSWR of the PA 316 on the transmission line 318 is implemented.

[0055] The transceiver system 214 can be coupled to the controller 360. The controller 360 can be implemented with one or more processors or microprocessors. In some implementations, the controller 360 can be implemented by the processor 204 Figure 2 ) of the base station 202.

[0056] The controller 360 can be coupled to the outputs of the voltage generators 358 from all of the transmit chains 310. While the voltage generators 358 are illustrated as being implemented in the detector 350, in other embodiments, the voltage generators 358 are implemented in the transmit chains 310, and the outputs of the voltage generators 358 are provided to the controller 360. Figure 3The outputs are shown as having separate coupling to the controller 360, but in some embodiments, one or more of the outputs (e.g., in some embodiments, all of the outputs) are coupled together and provided to the controller 360 through a single cable or interface. Prior to transmission from the phased array antenna, the processor 204 can implement a beamforming code for each of the transmit chains 310 that shifts the phase of the transmit signal to form a desired beam at the antenna system 216. For example, the phase shifters 312 can shift the phase of the respective versions of the transmit signal to cause constructive or destructive interference at the phased array during transmission. These beamforming codes can be stored in a codebook by the processor 204, such as in the memory 206.

[0057] The controller 360 can poll, cycle through, or interleave the inputs / measurements from all of the voltage generators (e.g., the s11 detector 350) to determine the best code for beamforming at the antenna system 216.

[0058] Figure 4 is Figure 2 and Figure 3 A graphical representation of an embodiment of an antenna system of In some implementations, the antenna system 216 can include a phased array of antenna elements 322. Based on changes or increases in reflected power or s11 determined by the detector 350, the controller 360 can disable one or more of the antenna elements 322 or disable the respective transmit chain 310 associated with s11 rising above a predetermined threshold. This can prevent damage to the PA 316 associated with elements 322 having high active s11. This can also reduce power consumption and improve overall efficiency of the antenna system 216. 25 antenna elements 322 are shown and labeled 1 through n. This number and arrangement of antenna elements 322 is not limiting to the present disclosure as other arrangements (e.g., linear, square, rectangular, circular, etc.) and numbers (e.g., 1-n) of antenna elements 322 are possible (n is an integer greater than 1).

[0059] Figure 5 is Figure 3 A graphical representation of an embodiment of a coupler of Figure 5 The low-directivity coupler 320 shown can be communicatively (e.g., inductively) coupled to the transmission line 318 Figure 3). In some implementations, the coupler input 502 is configured to receive a signal for transmission, which can be provided to the coupler 320 via the PA 316. The antenna element 322 can be coupled to the coupler output 504. The coupler 320 can be coupled to the transmission line 318 by an inductive coupling 506. The inductive coupling 506 can have a pair of elements 508a, 508b (collectively, elements 508). The elements 508 can include parallel wires or windings as desired. The coupler 320 has various advantages, including small size, which can improve implementation in smaller devices, such as smaller devices required for larger phased arrays.

[0060] The coupler 320 can have a first capacitance 512 coupled to the coupler input 502 (and a first port of the winding 508a). The coupler 320 can have a second capacitance 514 coupled to the coupler output 504 (and a second port of the winding 508a). The first and second capacitances 512, 514 can be capacitances based on electrical characteristics of the coupler 320 and electronic components to function as described herein. For example, in some implementations, the first and second capacitances 512, 514 can be individual explicit capacitors having values selected for particular impedance characteristics and tuning. In other embodiments, Figure 5 The capacitors 512, 514 shown represent capacitances present between components of the coupler 320, such as between the windings 508.

[0061] The coupler 320 can have a first capacitance 516 and an inductor 518 coupled to the first capacitance 512. The first capacitance 516 and inductor 518 (as well as the first capacitance 512) can also be coupled to a first port of the winding 508b. The first capacitance 516 and inductor 518 can be coupled in parallel to ground. The first capacitance 516 and inductor 518 can be referred to as a reflection impedance 510 (Z refl_tune ). This impedance can be tuned based on the operating frequency and process. In one example, the first capacitance 516 can be a first variable capacitance. In another example, the first capacitance 516 can be fixed.

[0062] The coupler 320 can have a second capacitance 526 and a resistance 528 coupled to the second capacitance 514. The second capacitance 526 and resistance 528 (as well as the second capacitance 514) can also be coupled to a second port of the winding 508b. The second capacitance 526 and resistance 528 can be coupled in parallel to ground. The second capacitance 526 and resistance 528 can be referred to as a coupling impedance 520 (Z couple_tune). In one example, the second capacitance 526 can be a second variable capacitance and / or the resistance 528 can be a variable resistance. In another example, the second capacitance 526 and / or the resistance 528 can be fixed. When one or more of the elements 516, 526, and 528 are tunable, in some embodiments, they can be adjusted by the controller 360 and / or the processor 204, e.g., based on a frequency of the signal through the coupler 320, a desired impedance, and / or to achieve balance, etc.

[0063] Figure 6 is in the first state Figure 3 a graphical representation of an embodiment of the detector 350. In Figures 6-8 The CS 352 is configured as a root mean square (RMS) current sensor (with differential inputs, as described above) in the illustrated embodiment, and can thus be referred to as a differential RMS current sensor (DRCS).

[0064] The DRCS 352 can have a pair of transistors 602, 612 coupled together at the drain. The sources of the transistors 602, 612 can be coupled to ground. The gate of the first transistor 602 can be coupled to a first input of the PA 316 to receive a first voltage (V_pdet_pa_inp) via a series capacitor 603. Switches 608 and 609 (s3 and s3A) can be disposed between the capacitor 603 and the first input V_pdet_pa_inp of the PA 316. The switch 608 (s3) can alternately couple the capacitor 603 to the first input of the PA 316. The switch 609 (s3A) can alternately couple the capacitor 603 to ground.

[0065] A resistor 607 can be coupled to the capacitor 603 and the gate of the transistor 602. A resistor 617 can be coupled to the capacitor 613 and the gate of the second transistor 612. The resistor 607 and the resistor 617 can be coupled to a pair of switches 621 (s6) and 622 (s6A). The switch 621 can alternately couple the resistors 607, 617 to a bias voltage V_p_det_bias. The switch 622 can alternately couple the resistors 607, 617 to ground.

[0066] The second transistor 612 can be coupled in an inverse configuration of the first transistor 602. The gate of the second transistor 612 can be coupled to the resistor 617 and a second input of the PA 316 (V_pdet_pa_inm) via the capacitor 613 and a pair of switches 618, 619. The switch 618 (s3) can alternately couple the capacitor 613 to the second input of the PA 316. The switch 618 (s3A) can alternately couple the capacitor 613 and the second input of the PA 316 to ground.

[0067] The drains of the first transistor 602 and the second transistor 612 can be coupled to a pair of switches 623 (s3), 624 (s3A). The switch 623 can alternately couple the drain of the first transistor 602 and the drain of the second transistor 612 to the voltage generator 358. The switch 624 can alternately couple the drain of the first transistor 602 and the drain of the second transistor 612 to ground.

[0068] In Figures 6-8 In the illustrated embodiment, the CS 354 is configured as a root mean square (RMS) current sensor, and can thus be referred to as an RCS. The RCS 354 can have a pair of transistors 604, 631. The sources of the transistors 604, 631 can be coupled to ground. The gate of the transistor 604 can be coupled to a capacitor 625. The capacitor 625 (on an opposite side) can be coupled to a pair of switches 626 (sl), 627 (slA). The capacitor 625 can be alternately coupled to the port C (or V_pdet_main) via the switch 626 (sl). The switch 627 (slA) can alternately couple the capacitor 625 to ground.

[0069] The gate of the transistor 604 can also be coupled to a resistor 628 (in addition to the capacitor 625). The resistor 628 (on an opposite side) can be coupled to a pair of switches 629 (s4A), 630 (s4). The switch 629 can alternately couple the resistor 628 to ground. The switch 630 selectively couples the transistor 604 to a bias voltage (V_p_det_bias).

[0070] The gate of the transistor 631 can be coupled to a capacitor 632. The capacitor 632 (on an opposite side) can be coupled to a pair of switches 636 (s2), 637 (s2A). The capacitor 632 is alternately coupled to the port D (or V_pdet_rvs) via the switch 636 (s2). The switch 637 (s2A) can alternately couple the capacitor 632 to ground.

[0071] The gate of the transistor 631 can also be coupled to a resistor 633. The resistor 633 (on an opposite side) can be coupled to a pair of switches 634 (s4), 635 (s4A). The switch 635 can alternately couple the resistor 633 to ground. The switch 634 selectively couples the transistor 631 to a bias voltage (V_p_det_bias).

[0072] The drain of the transistor 604 can be coupled to a pair of switches 601 (sl), 605 (slA). The switch 605 can alternately couple the drain of the transistor 604 to ground. The switch 601 can alternately couple the drain of the transistor 604 to the voltage generator 358.

[0073] The drain of transistor 631 can be coupled to a pair of switches 638 (s2), 639 (s2A). Switch 639 can alternately couple the drain of transistor 631 to ground. Switch 638 can alternately couple the drain of transistor 631 to voltage generator 358.

[0074] Voltage generator 358 can include output circuit 640 and bias circuit 660, as shown. Figures 6-8 Output circuit 640 has an input 641 coupled to switches 623 of DRCS 352 and switches 601, 638 of RCS 354. Input 641 can be coupled to ground via capacitor 642. Input 641 can be coupled to a reference current generator 644 (labeled Iref2) via inductor 643. Reference current generator 644 and inductor 643 can be coupled to a first input of amplifier 645.

[0075] The output of amplifier 645 can have a feedback loop with a parallel resistor 646 and capacitor 647 returning to the first input. Amplifier 645 can also receive a reference voltage (Vref) at a second input. The output of amplifier (V_pdet) can be coupled to controller 360. The output of amplifier V_pdet can be indicative of changes in reflected power experienced within the system. In some embodiments, output circuit 640 is configured as an RMS voltage generator.

[0076] Bias circuit 660 can have an amplifier 665. Amplifier 665 can receive a reference current (labeled Irefl) from a reference current generator 664 at a first input. Amplifier 665 can receive a reference voltage Vref as a second input. This reference voltage can be the same reference voltage as received at the second input of amplifier 645, or can be different. The output of amplifier 665 (V_pdet_bias) can be coupled to the gate of transistor 662. The source of transistor 662 can be coupled to ground. The source of transistor 662 can be feedback coupled to the first input of amplifier 665. The output of amplifier 665 (V_pdet_bias), and thus the output of bias circuit 660, can be provided to DRCS 352 (at switch 621). Because the conductive properties of electronic components can vary with environmental conditions, the bias voltage provided by bias circuit 660 can provide a baseline for normalizing variations caused by different environmental conditions. Bias circuit 660 can thus reduce the effects of environmental factor-based voltage and power level fluctuations within V_pdet.

[0077] While bias circuit 660 is shown in FIG. 6 as being separate from output circuit 640, in some embodiments, bias circuit 660 can be integrated into output circuit 640. Figures 6-8The bias circuit 660 is shown within the voltage generator 358, but alternatively, it can be implemented separately from the voltage generator 358. In some embodiments where the bias circuit 660 is separate from the voltage generator 358, the bias circuit 660 is still implemented in the detector 350, but in a separate block from the voltage generator 359. In other embodiments, the bias circuit 660 is implemented separately from the detector 350 and is configured to provide a reference voltage to the detector 350.

[0078] In the operation of detector(s) 350, controller 360 can sequentially enable antenna elements 322 of antenna system 216 and, for each PA 316 of each transmit chain 310, sense or measure the differential input voltage or Pdet_PA (e.g., the voltage across the inputs of PA 316). In beam characterization mode, this allows the system (e.g., controller 360) to characterize antenna system 216 and form a dynamic codebook, which controller 360 can reference during transmission. This can be implemented in each transmit chain 310, as follows: Figure 6 As shown in the first configuration. For example, switches 608, 621, 623 and 618 of DRCS 352a and switches 605, 639, 629, 635, 627 and 637 of RCS 354a are turned on (e.g., closed). Closed switches are marked with dashed circles.

[0079] Figure 7 yes Figure 6 The second state of the detector is graphically represented. In the second step of beam char mode, controller 360 can scan all values ​​of Pdet_MAIN for each transmit chain 310 and each antenna element 322 for each beam angle for a specified output power range. In this configuration, switches 609, 624, 619, and 622 of DRCS 352 can be closed / on (the rest off / on), while switches 626, 601, 639, 630, 635, and 637 of RCS 354 can be closed / on (the rest off / on). Closed switches are annotated with dashed circles. All elements can be scanned, or a subset can be scanned.

[0080] The controller 360 can enable each antenna element 322 in turn and measure Pdet MAIN and Pdet PA (for each antenna element 332) by setting a gain control index (e.g., automatic gain control (AGC) or RGI) to a linear output range. The linear output range can include a first threshold that sets a lower limit of the linear output range and a second threshold that sets an upper limit of the linear output range. If the difference between Pdet MAIN and Pdet PA is less than the first threshold, such a difference can indicate that the passive sll impedance is below the lower limit. If the difference between Pdet MAIN and Pdet PA is greater than the second threshold, such a difference can indicate that the passive sll impedance is greater than the upper limit. The upper and lower limits can be predetermined and based on the characteristics of the circuit. In both cases, the controller 360 can then remove the affected antenna element 322 from the codebook. If the difference between Pdet MAIN and Pdet PA is greater than the first threshold but less than the second threshold, the process can continue.

[0081] An antenna element 322 that is less than the first threshold or greater than the second threshold can be referred to as an “Ex” or element X. For a given beamforming pattern, the Ex element can be disabled during transmission.

[0082] As another example, if the function 10*log10(Pdet MAIN) - 10*log10(Pdet PA) for a given antenna element is less than a first threshold, such as a predetermined “low” threshold (e.g., threshold PA LO), such a difference can indicate that the passive sll impedance is below the lower limit. Conversely, if the function 10*log10(Pdet MAIN) - 10*log10(Pdet PA) for a given antenna element 322 is greater than a second threshold, such as a predetermined “high” threshold (e.g., threshold PA HI), such a difference can indicate that the passive sll impedance is greater than the upper limit (e.g., VSWR 2: 1 on the low impedance side). If 10*log10(Pdet MAIN) - 10*log10(Pdet PA) is greater than threshold PA LO but less than threshold PA HI, the process can continue. Thus, an antenna element 322 that is less than PA LO or greater than PA HI can be referred to as an “Ex,” and Pdet MAIN and Pdet PA can be referred to as Pdet MAIN Ex and Pdet PA Ex, respectively.

[0083] Figure 8 is Figure 6 a graphical representation of the third state of the detector. In the third step of the beam char pattern, the controller 360 can maintain the first and second thresholds at Figure 7The same settings (e.g., switch settings) within the DRCS 352 are shown, and each antenna element 322 is disconnected (e.g., deactivated based on the beamforming codebook settings, e.g., by zeroing the power provided to the element), to measure the voltage reflected from each antenna element 332 (Pdet_RVS). This can determine whether one or more of the antenna elements 322 does not meet a reverse power level threshold. That is, whether the value Pdet_RVS is above a predetermined threshold. Such elements can be referred to herein as Ey (element y).

[0084] In the illustrated configuration, the switches 609, 624, 619, 622 of the DRCS 352 can be closed / conducting (the rest of the switches are open / nonconducting), while the switches 605, 627, 629, 638, 634, 636 of the RCS 354 can be closed or conducting (the rest of the switches are open / nonconducting). The closed switches are annotated with a dashed circle.

[0085] If the difference between Pdet_RVS and Pdet_MAIN for a given antenna element is greater than a predetermined reverse power threshold, then the coupling from other elements is greater than the main transmit signal by a given limit, and is therefore undesirable from a reliability and current consumption perspective. In this case, the element 322 is referred to as Ey, and can be listed in the codebook. If the difference between Pdet_RVS and Pdet_MAIN for an antenna element is less than a predetermined reverse power threshold, then it performs under the proper operating limit, and can be moved to the next element of the corresponding codebook. The process proceeds to the next step. Each element of each codebook can be checked in this way.

[0086] For example, if E_ACTIVE - S11 = 10 · Log 10 (Pdet_RVS) - 10 · Log 10 (Pdet_MAIN), where E refers to a given element, is greater than a predetermined reverse power threshold (threshold_REVS), then the coupling from other elements is greater than the main transmit signal by a given limit, and is therefore undesirable from a reliability and current consumption perspective. In this case, the element 322 is referred to as Ey, and can be removed from the codebook, while Pdet_MAIN and Pdet_PA can be referred to as Pdet_MAIN_Ey and Pdet_PA_Ey, respectively.

[0087] If E_ACTIVE - S11 = 10 · Log 10 (Pdet_RVS) - 10 · Log 10(Pdet_MAIN) is less than a predetermined reverse power threshold (threshold REVS), it is below the safe operating limit, and can move to the next element of the corresponding codebook. The process proceeds to the next step. Each element of each codebook can be checked in this manner.

[0088] Figure 9 is a flowchart of an embodiment of a method for detecting and managing active s11 in a phased array antenna according to the present disclosure. The method 900 can be performed by, for example, the controller 360.

[0089] At block 935, the controller 360 can receive a codebook for a given set of beamforming codes. In example implementations, at optional block 905, the controller 360 can select an antenna element 322 from the phased array antenna system 216. The method 900 can optionally be iteratively performed to keep the codebook up to date. Embodiments herein can detect high active s11 for a given antenna element, and adjust the transmission power level, and enable / disable individual antenna elements 322 (e.g., and associated transmit chains 310), for example, based on the beamforming codebook settings, based on the power levels measured by the detector 350, turning off each element.

[0090] In some implementations, at block 910, the controller 360 can determine a differential voltage at the input of the PA 316 during a transmit operation (Pdet PA). As used herein, this voltage difference is simply referred to as Pdet PA (e.g., power detector, power amplifier). The voltage sensed by the CS 352 is provided as a current to the voltage generator 358. While shown prior to block 935, block 910 can be performed after the codebook is received at 935.

[0091] In some implementations, at optional block 915, the controller 360 can optionally determine whether the gain of the element being tested is greater than a threshold high power level (threshold PA HI) or lower than a threshold low power level (threshold PA LO). If so, at optional block 920, the controller 360 can remove the element 322 (Ex) from the codebook, and proceed to the end of the method 900. If not, the method can proceed to optional decision block 925. Note that the element Ex will not be used for transmission in the measured set of beamforming codes going forward.

[0092] At optional block 925, the controller 360 can optionally determine whether there are more elements 322 to test, and return to selecting the next antenna element 322. Based on the configuration of the switches within the CS 352 and the CS 354 (e.g., Figure 6The controller 360 can sense Pdet PA and interleave samples of Pdet PA from each transmit chain 310 and thus from each antenna element 322. If there are no more elements 322 to test, the controller 360 can optionally select a next codebook at optional block 930.

[0093] At block 935, the controller 360 can receive a codebook. For example, the received codebook can be the selected next codebook described above; however, the codebook can be any provided or selected codebook and need not be selected according to the example described above. At block 940, the controller 360 can individually test elements 322 for a given beamforming angle according to the received codebook. For example, the controller 360 selects the antenna elements from the elements 322 to be tested.

[0094] At block 945, the controller 360 can turn off each element based on the beamforming codebook settings. The controller 360 can then measure the signal voltage provided to each antenna element (Pdet MAIN) for each beam angle in the codebook.

[0095] At block 950, the controller 360 can measure the reflected voltage level for each antenna element (Pdet RVS) for each beam angle in the codebook.

[0096] As described above, the controller 360 can determine the differential voltage (Pdet PA) after block 935, for example, concurrently with, before, or after blocks 945 and / or 950.

[0097] At block 955, the controller 360 can determine the active sll for each antenna element 322 based on the measured Pdet MAIN and Pdet RVS, for example, as described above in connection with Figure 8 the description.

[0098] At decision block 960, if the active sll is greater than a threshold (threshold RVS), the element can be referred to as Ey and can be removed from the codebook at block 965.

[0099] If at decision block 960, the active sll is less than or equal to the threshold RVS, the method 900 can move to decision block 970.

[0100] At decision block 970, if there are more elements to test in the codebook, the method 900 returns to block 940. Otherwise, the process 900 can end.

[0101] In example implementations, after block 970, if there are no more elements in the codebook to test, at optional block 975, the controller can optionally determine whether there are more codebooks to test. If there are more codebooks to test, the controller 360 can return to selecting the next codebook at optional block 930, as described above in optional embodiments. Otherwise, if there are no more codebooks to test, the controller 360 can optionally update the beamforming lookup table of the codebook for each beamforming angle using the elements 322. For example, the beamforming lookup table for each angle can be updated to include or exclude the antenna elements based on their inclusion or exclusion in each codebook. In addition, such updates can also be based on the removal of elements as described above in optional embodiments and the inclusion of elements to the respective codebook at block 970. The controller 360 can then optionally invert the beamforming lookup table, for example, by repeating the method 900 as necessary with or without the optional embodiments described above. Finally, the controller 360 can optionally cause transmission from the antenna system 216 based on the codebook.

[0102] In one example, removing the element Ex can include removing a reference to the element Ex in the codebook. Thus, the beamforming code for a given antenna element can not be in the codebook and can not be included in the updated lookup table. In this way, the element Ex can not be activated to form a beam at a given angle, where the element Ex is excluded from the codebook and, thus, from the lookup table. In another example, removing the element Ex can include setting the beamforming weight to zero (e.g., zeroing the power used to drive the element Ex). Thus, while the element Ex can still be listed in the codebook, it is deactivated and essentially excluded from forming a beam.

[0103] Other Aspects

[0104] The accompanying claims and their equivalents are intended to encompass such forms or modifications as fall within the range of the disclosure. The various components illustrated in the figures can be implemented, for example, but not limited to, software and / or firmware on a processor or dedicated hardware. Moreover, features and attributes of the specific example embodiments disclosed above can be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure.

[0105] The above method descriptions and process flow diagrams are provided only as illustrative examples, and do not require or imply that operations must be performed in the order described. As will be appreciated by one of skill in the art, the order of the above-described operations can be changed, and / or two or more operations can be performed at the same time. Words such as "thereafter," "then," "next," etc. are used only to guide the reader through the description. These words are not intended to limit the order of the operations described. Further, any reference to claim elements in the singular, for example, using the articles "one," "the," "said," and "the," is not construed as limiting the component to the singular.

[0106] The various illustrative logical blocks, modules, and algorithm operations described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, and operations have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present inventive concepts.

[0107] The hardware used to implement various illustrative logics, logical blocks, and modules described in connection with the embodiments disclosed herein can be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field

[0108] In one or more exemplary embodiments, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored as one or more instructions or code on a non-transitory computer-readable storage medium or a non-transitory processor-readable storage medium. The operations of a method or algorithm disclosed herein can be embodied in a processor-executable instruction that can reside on a non-transitory computer- or processor-readable storage medium. Non-transitory computer- or processor-readable storage media can be any storage media that can be accessed by a computer or a processor. By way of example but not limitation, such non-transitory computer- or processor-readable storage media can include RAM, ROM, EEPROM, FLASH memory, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc, as used herein, includes compact discs (CD), laser discs, optical discs, digital versatile discs (DVD), floppy disks and blu-ray discs where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of non-transitory computer- and processor-readable media. Additionally, the operations of a method or algorithm can reside in one or any combination of the above memory or storage media, which can be incorporated in computer-program products.

[0109] It should be understood that the particular order in which the steps of disclosed processes have been presented is exemplary. It is possible that the steps of the processes can be re-ordered, combined, or eliminated, based on design considerations. Furthermore, some steps can be performed simultaneously. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

[0110] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects.

[0111] Thus, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." Depending on the context, singular or plural references can be used to simplify the generality of elements that can be singular, or plural.

[0112] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term "some" refers to one or more.

[0113] Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, and can include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" can be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combination can contain one or more member of A, B, or C.

[0114] While certain example embodiments and applications have been shown and described herein, other embodiments and applications that are within the scope of the disclosure will be apparent to those of ordinary skill in the art from the description and drawings herein. Therefore, the scope of the disclosure should be interpreted in the light of the appended claims and their equivalents.

Claims

1. An apparatus coupled to an antenna element of a plurality of antenna elements of a phased array antenna, the apparatus comprising: a power amplifier (PA) having an output coupled to the antenna element of the plurality of antenna elements via a transmission line; a first current sensor coupled to an input of the PA, the first current sensor configured to convert a voltage at the input to a first current; a second current sensor in communication with the transmission line, the second current sensor configured to convert a coupled voltage corresponding to a signal transmitted from the PA to the antenna element to a second current, and convert a reflected voltage reflected from the antenna element to a third current; and a voltage generator coupled to the first current sensor and the second current sensor and configured to convert the first current, the second current, and the third current to an output voltage at an output of the voltage generator.

2. The apparatus of claim 1, further comprising a coupler coupled to the transmission line by an inductive coupling and configured to provide the coupled voltage and the reflected voltage to the second current sensor.

3. The apparatus of claim 2, wherein the coupler comprises a compact coupler having a reflected impedance comprising a first variable capacitance coupled in parallel with a first inductance, the reflected impedance coupled between a first port of a conductor or winding in the inductive coupling and ground, and a coupled impedance comprising a second variable capacitance coupled in parallel with a variable resistance, the coupled impedance coupled between a second port of the conductor or winding in the inductive coupling and ground.

4. The apparatus of claim 1, wherein the first current sensor comprises a first plurality of switches selectively coupling the input of the PA to a first pair of transistors.

5. The apparatus of claim 4, wherein the first plurality of switches communicatively couple the input of the PA to the voltage generator via the first pair of transistors in a first position and electrically isolate the input of the PA from the first current sensor in a second position.

6. The apparatus of claim 4, wherein the second current sensor comprises a second plurality of switches selectively coupling the transmission line to a second pair of transistors.

7. The apparatus of claim 6, wherein the second plurality of switches enable the second current sensor to produce the second current corresponding to the coupled voltage in a first position and the third current corresponding to the reflected voltage in a second position.

8. The apparatus of claim 1, wherein the voltage generator comprises: a biasing circuit coupled to the first current sensor and the second current sensor, and an output circuit coupled to the first current sensor and the second current sensor.

9. A communication apparatus comprising a phased array antenna having a transmit path for each antenna element of the phased array, wherein each transmit path comprises the apparatus of claim 1.

10. The communication device of claim 9, further comprising a controller configured to selectively activate and deactivate one or more of the plurality of antenna elements based on the output voltage.

11. An apparatus for detecting an active return loss of each of a plurality of antenna elements of a phased array antenna, the apparatus comprising: a component for amplification coupled to each of the plurality of antenna elements via a transmission line; a first sensing component for sensing a voltage at an input of the component for amplification and converting the voltage at the input of the component for amplification to a first current; a second sensing component for sensing a voltage on the transmission line, the second sensing component comprising a component for converting a coupled voltage corresponding to a signal transmitted from the component for amplification to a respective antenna element to a second current, and a component for converting a reflected voltage reflected from the respective antenna element to a third current; and a component for generating a voltage based on the first current, the second current, and the third current.

12. The apparatus of claim 11, further comprising a coupling component coupled to the transmission line by an inductive coupling and configured to provide the coupled voltage and the reflected voltage to the second sensing component.

13. The apparatus of claim 12, wherein the coupling component comprises a low-directivity coupler having a reflected impedance comprising a first variable capacitance coupled in parallel with a first inductance, the reflected impedance coupled between a first port of a conductor or winding in the inductive coupling and ground, and a coupled impedance comprising a second variable capacitance coupled in parallel with a variable resistance, the coupled impedance coupled between a second port of the conductor or winding in the inductive coupling and ground.

14. The apparatus of claim 11, wherein the first sensing component comprises a first plurality of switches selectively coupling the input of the component for amplification to a first pair of transistors.

15. The apparatus of claim 14, wherein the first plurality of switches communicatively couple the input of the component for amplification to the component for generating a voltage via the first pair of transistors in a first position and electrically isolate the input of the component for amplification from the first sensing component in a second position.

16. The apparatus of claim 14, wherein the second sensing component comprises a second plurality of switches selectively coupling the transmission line to a second pair of transistors.

17. The apparatus of claim 16, wherein the second plurality of switches enable the second sensing component to produce the second current corresponding to the coupled voltage in a first position and the third current corresponding to the reflected voltage in a second position.

18. The apparatus of claim 11, wherein the component for generating a voltage comprises: a biasing circuit coupled to the first sensing component and the second sensing component, and an output circuit coupled to the first sensing component and the second sensing component.

19. A communication device comprising a phased array antenna having a transmission path for each antenna element of the phased array, wherein each transmission path comprises the apparatus of claim 11.

20. A three-mode power detector coupled to a plurality of antenna elements of a phased array antenna, the three-mode power detector comprising: a differential RMS current sensor configured to convert a first voltage difference across an input of a power amplifier (PA) to a first current, the PA coupled to a respective antenna element of the plurality of antenna elements via a transmission line; an RMS current sensor configured to convert a coupled voltage corresponding to a signal transmitted from the PA to the respective antenna element to a second current, and convert a reflected voltage corresponding to a signal reflected from the respective antenna element to a third current, and a voltage generator coupled to the differential RMS current sensor and the RMS current sensor and configured to convert the first current, the second current, and the third current to an output voltage at a generator output.

21. The three-mode power detector of claim 20, further comprising a coupler coupled to the transmission line by an inductive coupling and configured to provide the coupled voltage and the reflected voltage to the RMS current sensor.

22. The three-mode power detector of claim 21, wherein the coupler comprises a low-directivity coupler having a reflected impedance comprising a first variable capacitance coupled in parallel with a first inductance, the reflected impedance coupled between a first port of a conductor or winding in the inductive coupling and ground, and a coupled impedance comprising a second variable capacitance coupled in parallel with a variable resistance, the coupled impedance coupled between a second port of the conductor or winding in the inductive coupling and ground.

23. The three-mode power detector of claim 20, wherein the differential RMS current sensor comprises a first plurality of switches selectively coupling the input of the PA to a first pair of transistors.

24. The three-mode power detector of claim 23, wherein the first plurality of switches communicatively couple the input of the PA to the voltage generator via the first pair of transistors in a first position and electrically isolate the input of the PA from the differential RMS current sensor in a second position.

25. The three-mode power detector of claim 23, wherein the RMS current sensor comprises a second plurality of switches selectively coupling the transmission line to a second pair of transistors.

26. The three-mode power detector of claim 25, wherein the second plurality of switches enable the RMS current sensor to produce the second current corresponding to the coupled voltage in a first position and the third current corresponding to the reflected voltage in a second position.

27. A method for detecting an active return loss of an antenna element of a plurality of antenna elements of a phased array antenna, the method comprising: converting a voltage to a first current, the voltage sensed by a first current sensor coupled to an input of a power amplifier (PA), wherein the PA has an output coupled to the antenna element of the plurality of antenna elements via a transmission line; converting, by a second current sensor in communication with the transmission line, a coupled voltage corresponding to a signal transmitted from the PA to the antenna element to a second current; converting, by the second current sensor, a reflected voltage reflected from the antenna element to a third current; and converting, by a voltage generator coupled to the first current sensor and the second current sensor, the first current, the second current, and the third current to an output voltage at an output of the voltage generator.

28. The method of claim 27, further comprising providing the coupled voltage and the reflected voltage to the second current sensor via a coupler coupled to the transmission line by inductive coupling.

29. The method of claim 28, wherein the coupling comprises a compact coupler having a reflected impedance comprising a first variable capacitance coupled in parallel with a first inductance, the reflected impedance coupled between a first port of a conductor or winding in the inductive coupling and ground, and a coupled impedance comprising a second variable capacitance coupled in parallel with a variable resistance, the coupled impedance coupled between a second port of the conductor or winding in the inductive coupling and ground.

30. The method of claim 27, wherein the first current sensor comprises a first plurality of switches, and the method further comprises selectively coupling the input of the PA to a first pair of transistors. ​ ​ ​

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