Precision self-calibration of phased array antennas

Abstract

To provide a method of self-calibration for a phased array antenna that achieves the same output power (Pout) for all antenna elements in a system.SOLUTION: At step 1001, the method includes the calibration circuit powering off all active circuits and power amplifiers of the RFIC. At step 1002, the calibration circuit powers on the active circuits of the RFIC being calibrated and monitors the current consumption of the active circuits. In step 1003, the calibration circuit measures the bias current of the active circuit and adjusts the bias current to a predetermined level during calibration. At step 1004, the calibration circuitry repeats the calibration of the bias current for each active circuit of the RFIC and for all RFICs in the phased array antenna.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a division of U.S. Patent No. 5,699,669, entitled "Phase-Array Antenna P "Section Self-Calibration" This application claims priority to and is based on U.S. Provisional Patent Application No. 63 / 246,221, filed on the 0th day of this patent application. is incorporated herein by reference.

[0002] The disclosed embodiments relate generally to phased array antennas, and more particularly to phased array antennas. This invention relates to a method of self-calibration for a square array antenna. [Background technology]

[0003] In antenna theory, a phased antenna array typically generates a beam of radio waves. It refers to an array of antennas, which can be electronically adjusted to point in different directions without moving the antennas. Beamforming is a technology that directs wireless signals in a specific direction. The phase and amplitude of each signal are determined by the energy The high power signals add constructively and destructively in such a way as to concentrate the high power signals into a narrow beam or lobe. In the case of multiple array antennas operating in a dense area, each array antenna is In the case of a multi-beam array antenna, Each antenna beam points in a specific direction. Mobile operators are increasingly experiencing bandwidth shortages. It has become clear that approximately A motion to explore the unused millimeter wave (mmWave) frequency spectrum from 24 GHz to 300 GHz It supports directional communications using narrow beams in millimeter wave networks. To achieve this, 5G base stations will use phased array antennas to support multiple beams. are.

[0004] A typical phased array antenna configuration uses multiple radio frequency integrated circuits (RFICs) For example, a beamforming RFIC is used. Each signal path for an antenna element is Includes fixed and variable gain RF amplifiers and phase shifters to perform precision phased array functions Therefore, the amplifier gain and the phase shifter in each antenna element must be precisely controlled. However, the RF amplifier in the RFIC: 1) typically suffers from a few dB of distortion if not compensated; PVT variations (variations in wafer process, supply voltage, and temperature) and 2) random variations due to size variations of transistors or passive elements. Therefore, this requirement is typically set at the minimum for transistors, capacitors, and resistors used within an RFIC. Subject to random variations, which is met by limiting the size of the antenna. To meet the high accuracy requirement for amplitude tapering across the array (e.g., 0.375 dB), The RFICs and RF amplifiers across the antenna array need to be calibrated.

[0005] Calibrating a phased array antenna system in an over-the-air (OTA) setting is highly challenging for the following reasons: It is expensive and complicated because: 1) it requires an RF anechoic chamber; 2) it requires far-field The chamber can significantly speed up calibration, but the antenna chamber is very large for large arrays. 3) the gain and phase of each individual signal path (corresponding to each antenna element) 4) It is necessary to calibrate so many conditions that the 5) Adjustment and calibration require additional time and cost for the system. The need to have sufficient gain adjustment range and gain resolution available. To reduce the cost of antenna calibration after manufacturing, the RFIC is designed for different manufacturing processes. self-calibrated by automated test equipment or calibrated during the manufacturing process It is desirable to have a self-calibrating system that does not require OTA / chamber setup. is desired. Summary of the Invention [Problem to be solved by the invention]

[0006] RFI implemented in CMOS, CaAs, SiGe, and other silicon processes Radio frequency (RF) circuit design (amplifiers, mixers, etc.) using C is a Variations in performance due to temperature, supply voltage, and random variations There are problems with gain, phase, frequency, bandwidth, and nonlinearity. In a transmitter, it is important to maintain near-identical performance for each RFIC and each signal path. Phase array antenna radio testing requires expensive antenna chambers and takes a long time. In the present invention, the bias voltage of all active devices in the system is A method has been proposed to precisely calibrate the current and the gain of the individual signal paths leading to each amplifier. As a result, the same Pout is achieved for all antenna elements in the system. The calibration involves current measurements only, and no test equipment or over-the-air (OTA) testing is used. Note that such calibration can therefore be done in the field or at the factory, and is suitable for mass production. This significantly reduces test time in the chamber. [Means for solving the problem]

[0007] In one embodiment, the calibration circuitry comprises all active components on the RFIC of the phased array antenna. The calibration circuitry and power amplifier are powered off. The calibration circuitry is The circuit is powered on and the current draw of the active circuit is monitored. The bias current of the circuit is measured and adjusted to a predetermined level during calibration. The path is connected to each active circuit in the RFIC and to the entire RF Repeat bias current calibration for IC.

[0008] In another embodiment, the calibration circuitry is configured to calibrate all active components on the RFIC of the phased array antenna. Turn off the power to the power amplifier and the RFIC being calibrated. The corresponding signal path leading to the amplifier is powered on. The calibration circuitry The calibration circuit provides an input signal to measure the follow-on current of the power amplifier during calibration. The amplifier gain and output power of the corresponding signal path leading to the power amplifier are adjusted until the desired follow current of the amplifier is reached. The calibration circuit adjusts the power by measuring the RFI level using the same input signal with a predetermined signal level. For each power amplifier and corresponding signal path of C, and for all R Repeat the output power calibration for the FIC.

[0009] Other embodiments and advantages are described in the detailed description below. The present invention is defined by the claims. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a simplified block diagram of a typical transmit phased array antenna configuration for a base station having a self-calibration mechanism, according to one aspect. [Figure 2] Shown is an RFIC bias generation system that generates bias currents used in RF amplifier circuits. [Figure 3] FIG. 1 is a simplified circuit diagram of a bias generator that supports a constant gm bias used in a radio frequency amplifier in an RFIC. [Figure 4] 1 illustrates an embodiment of a current measurement circuit that can be used for bias current calibration in a phased array antenna. [Figure 5] 10 is a flowchart of a procedure for self-calibrating bias currents in a phased array antenna according to another aspect. [Figure 6] 1 illustrates an embodiment of a bias current self-calibration system for a phased array antenna according to another aspect. [Figure 7] 1 shows the follow current for various power amplifier classes and the appropriate back-off operating points for the power amplifiers. [Figure 8] 10 is a flowchart of a procedure for self-calibrating output power in a phased array antenna according to another aspect. [Figure 9] 1 illustrates an embodiment of an output power self-calibration system for a phased array antenna according to another aspect. [Figure 10] 10 is a flowchart of a method for self-calibrating bias currents of active circuits on an RFIC of a phased array antenna according to another embodiment. [Figure 11] 10 is a flowchart of a method for self-calibrating the output power of a power amplifier on an RFIC of a phased array antenna according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Reference will now be made in detail to certain embodiments of the present invention, examples of which are illustrated in the accompanying drawings. It is being done.

[0012] FIG. 1 illustrates a typical transmission phase of a base station 101 having a self-calibration mechanism, according to one embodiment. A simplified block diagram of a door array antenna configuration. The mobile communication network 100 includes a base station BS101, a user equipment user equipment (UE) 102, and a user equipment user equipment (UE) 103. A cellular mobile communication network includes a plurality of user equipments. The cellular mobile communication network uses directional communication with narrow beams. It can use IEEE 802.11b / g and support multi-gigabit data rates. An example of a cellular network is a millimeter wave (mmWave) network, which uses millimeter wave frequencies In such a millimeter wave network, beamforming is used. Directional communication is achieved by using multiple antennas to form multiple beam patterns. A phased antenna array 110 having multiple elements is provided with multiple sets of beamforming weights. (phase shift values) are applied, which overcome the high path loss in mmWave networks, It is required to provide mobility support for mobile terminals. In the example of Figure 1, Phased antenna array 110 serves mobile stations including UE 102 and UE 103. To provide a set of coarse TX / RX control beams (130) and a set of dedicated TX / RX The data beam (140) is configured directionally.

[0013] In the example of FIG. 1, BS 101 is coupled to combiner / splitter network 120. The phased array antenna 110 is a multi-antenna array that operates in a high-density area. In the case of an array antenna, each array antenna generates its own beam to point at a specific UE (direction). In a typical phased array antenna configuration, beamforming RFICs and other Multiple radio frequency integrated circuits (RFICs) are used. Each RFIC contains an antenna element. Each signal path for an antenna element includes a fixed and variable gain amplifier. and a phase shifter. To operate the precision phased array function, the amplifier gain and each The phase shifters in the antenna elements must be precisely controlled. The RF amplifier in C: 1) has PVT variations that would normally vary by several dB if uncorrected; (variations in wafer process, supply voltage, and temperature), and 2) transistor Or random variations due to size variations of passive elements and threshold variations, The requirements are typically for the minimum size of transistors, capacitors, and resistors used within an RFIC. The desired sideloop is satisfied by limiting the The amplitude tapering of the entire antenna array (0.3 To meet high accuracy requirements (less than half of 75dB), RFIC for the entire antenna array It is necessary to calibrate the active circuitry with

[0014] Calibrating a phased array antenna system in an over-the-air (OTA) setting is important because: It is expensive and complex because: 1) it requires an RF anechoic chamber; 2) it is far away; Field chambers can significantly speed up calibration, but large arrays require very large antenna chambers. 3) the need for a test range or field test; Precision measurements to determine the gain and phase of each individual signal path (corresponding to each antenna element) 4) A large number of conditions must be calibrated, which means the calibration time is long and the system is 5) the need for sufficient gain adjustment range and available power for adjustment and calibration. The manufacturing complexity and post-manufacturing antenna comparison are key issues. To reduce manufacturing costs, RFICs are self-correcting or designed for different manufacturing processes. Or calibrated during the manufacturing process by simple automated test equipment that only requires DC measurements. It is desirable to have a self-calibrating system that does not require OTA / chamber setup. It is hoped that this will happen.

[0015] According to another aspect, a phased array antenna having an RFIC with precision self-calibration In a first novel aspect, a calibration control procedure is proposed for the controller. current meters, switches, and bias currents in phased array antennas. It is proposed that the active element in the system be connected to a calibration circuit, which comprises a phase adjustment circuit. The bias current of the circuit is self-calibrated after power-up. Initially, all active circuits are turned off. One by one, selected individual active circuits are turned on and their The bias current of the circuit is measured by a current meter in the system. It includes a current regulation circuit (i.e., a current DAC "digital-to-analog converter") that regulates the The bias current of the selected active circuitry is and adjust the current DAC settings in the controller until the desired accuracy is achieved. Calibration can be repeated until the bias currents of all active circuits in the system are calibrated. In the second novel aspect, the output of each signal path in the phased array antenna system is A self-calibration procedure for power is proposed. All power antennas corresponding to all antenna elements in the system are The gain of each individual path is precisely calibrated so that the same output power is achieved for the amplifier.

[0016] Figure 2 shows the RFIC bias circuit that generates the constant bias current used in the RF amplifier circuit. The RFIC bias generation system 200 provides a constant voltage. The bandgap (BG) voltage source 201 is connected to a V-To-I circuit 202. The global reference current is converted into a constant current (called the global reference current) by After that, it is used by the global one-to-many mirroring circuit 203 to It generates many mirroring currents such as 00μPE, which are connected to multiple reference currents 1, 2, ~ and the like. The current is then applied to the amplifier circuit via a mirrored or replica bias circuit 205. Each individual circuit generates a bias current proportional to the reference current. Custom designed mirrored or replicated bias circuits to generate the desired bias current For example, the bias current of the active circuit 1 is 1, the bias current of the active circuit 2 is 2, and so on. Ideally, each bias current is equal to the desired constant bias voltage. It must have a high flow rate.

[0017] The gain of a transistor amplifier depends on 1) the transistor size and the width-to-length (W / L) ratio ( The larger the transistor size, the higher the If used, the rate of size variation will be reduced, and 2) the transistor amplifier will operate. Determined by the bias current. Achieving a precision bias current in an amplifier is shown in Figure 2. To achieve this, the RFIC typically implements a bias generation system 200, which: 1) Reference voltage / reference current conversion; 2) One-to-multiple reference current mirroring and 4) the delivery of a reference current to each individual amplifier. A mirroring or replicating circuit is used to adjust the reference current to the desired operating bias current. bias currents are primarily due to errors in the mirroring or replicating circuits. One of the factors that affect the Vth threshold voltage is the random variation between transistors. Even if manufacturing variations in transistor size are acceptable, the Vth threshold Variations in the value voltage can affect the accuracy in the bias current.

[0018] Figure 3 shows the constant gm bias used in the radio frequency amplifiers in the RFIC. 1 is a simplified circuit diagram of a bias generator 301. The bias generator 301 is a pair of transistors. The gates of M1 and M2 are connected to an external resistor R EXT By Transistor M1 has a size of W / L, and transistor M2 has a size of K*(W / L). As shown in Figure 3, the size of the constant G m The bias is R EXT and Trans is determined only by the size ratio K, and g m =2 / R EXT *(1-1 / √K), Here R EXT is a precision resistor with zero temperature coefficient. Since the voltage is independent of PVT, the constant current generated using these parameters is also P It is independent of VT and can therefore be used as the main bias current for large RFICs. In Figure 3, Iref1 and Iref2 are different bias voltages used in different RF amplifiers. It is a cross current mirror.

[0019] To obtain a precise value of Gm, the size ratio K between transistors M1 and M2 must be Note that the value of Gm is very important. Also, transistor M1 must be a good transistor with Gm. To maintain matching, the transistors used in the RF amplifier must be replicated. Therefore, it is very important to use the same type and size of transistors. As a result, transistor M2 is a transistor with the same K and the same size (W / L). It is formed by replicating the transistor M1. Furthermore, the current density of the transistor is , must be the same as the current density of the RF amplifier. Therefore, if the transistor size is By increasing the size ratio K, the accuracy can be improved, while the size can be made smaller with lower power consumption. For RFIC implementations, it is desirable to have large M1 and M2 transistors. Not likely.

[0020] As explained above, a constant Gm bias ensures that the amplifier transconductors across the wafer Precise and temperature-stable off-chip resistors on each RFIC are used to maintain the gain. Resistors are used as a reference and transistor size ratios are used to obtain precise Gm. However, the accuracy is limited by the transistor threshold voltage V th It is affected by variations in CM In OS semiconductor processes, the threshold voltage V th Even within the same wafer, The transistor threshold voltage of M1 is V th,1 and the M2 transistor The threshold voltage is V th,2As shown in Figure 2, this is the reference current to the mirror line. Errors in amplifier bias currents created by the biasing circuit or replica bias circuit Errors in amplifier bias current affect amplifier performance, e.g. , Gm is the square root of the bias current. Therefore, to improve the performance of the amplifier, This requires accurate calibration of the error in the pulse current.

[0021] In one embodiment, P A TAT (proportional to absolute temperature) current source is used, which is temperature independent (or temperature often used to generate bias voltages (voltage dependent) and as a reference for measurement systems, It is also used in intra-bandgap reference circuits. The bias current can be increased or decreased as a function of temperature. can be reduced, and the Gm of the transistor can be adjusted to maintain its performance over temperature. Compensate for variations in the transconductance gain.

[0022] Figure 4 shows a current measurement circuit that can be used as a self-calibration system for a phased array antenna. 4 shows an embodiment of a flow meter 400. The self-calibrating system performs phased calibration after power-on. The self-calibrating system self-calibrates the bias current of the power amplifier in the array antenna. , a μC with an analog-to-digital converter (ADC) and a precision resistor R In addition to measuring the voltage drop across the body, the μC can also control the on / off and The self-calibration system controls the bias of each individual circuit. Turns on / off the main power management system that supplies voltage to the RFIC The RFIC has the ability to control bias generation in order to When set to ON, a separate supply voltage is provided for calibration purposes.

[0023] Calibration is done one circuit at a time, i.e., precise voltage measurement by the ADC (typically in the μC). To allow measurement of the current (i.e. the voltage drop across the precision resistor), the current to be measured Each circuit uses a mirrored link to adjust the bias circuit under the control of the μC. A current DAC is included to inject a correction current into the bias circuit or replica bias circuit. The main reason for using the supply voltage is to avoid unnecessary power consumption during operation (after calibration is complete). This is to avoid this precision resistor in the main power path, which may cause The bias current can be adjusted during calibration until it reaches a predetermined level within the acceptable range.

[0024] In the example of FIG. 4, the current measurement circuit 400 includes a μC, an ADC, an iDAC, and a precision R. The μC uses an ADC to measure the current I to measure the voltage V across a precision resistor R. Measure the resistance, e.g., I=V / R. The precision resistor R prevents power dissipation during normal operation. To avoid this, the main voltage source of the system is switched off and the auxiliary voltage source for calibration is switched on during the measurement. The µC continues to measure the current digital / analog until the desired bias current is measured. Adjust the logarithmic converter (iDAC). For example, adjust the iDAC until the desired bias current is achieved. A 4- to 6-bit control signal can be used to adjust C. Note that the amplifier or active circuitry can be turned on and off under μC control. This measurement is performed on each active circuit in the system while all other circuits are turned off. is repeated for

[0025] FIG. 5 illustrates a bias voltage for a power amplifier in a phased array antenna according to another embodiment. 5 is a flowchart of a procedure for self-calibrating the flow. Step 501 is an initialization stage. The self-calibration system: 1) turns off all amplifier circuits; 2) turns off the DC supply voltage to all RFICs; All regulators supplying pressure are turned off, and the process proceeds to step 502. One by one, the self-calibration system turns on each power amplifier and adjusts the bias current. 1) Self-calibration, global bias generators, and bias voltages associated with selected circuits. 1) Turn on the voltage source for the generator and measure the current; 2) Turn on the selected active circuit. 3) monitor the current consumption increase of selected circuits; and 4) the self-calibration system (iDAC setting). (by changing the bias setting of each active device) until the desired accuracy is reached. Adjust the current.

[0026] FIG. 6 illustrates a bias current self-calibration system for a phased array antenna according to another embodiment. 6 shows an embodiment of a self-calibrating system 600. The self-calibrating system 600 is similar to the current measurement circuit 400. The comparison is based on a single power supply divided into four power domains, with three different supply voltages for operation. An additional regulator and switch are implemented for the positive circuit (system under test). For example, by controlling the voltage with a regulator and switch, it is possible to , and 3.3 volts can be individually calibrated, e.g., to The four power domains are also compared individually to reduce power consumption by controlling them with a switch. This allows for calibration to be repeated for each power domain, making it possible to During calibration, all circuits are turned off except for the one being tested. For each circuit, the voltage drop is adjusted until the desired voltage drop is achieved as measured by the ADC. Adjusts the DAC bias in the current mirror.

[0027] Self-calibration is done in the foreground, meaning that the phased array antenna system is typically Note that the self-calibration is not in normal operation. It can be done while the system is idle or during maintenance. Self-calibration is a precision calibration for the amplifier. A fine bias current can be achieved, which in turn means a fine amplifier gain can be achieved. The self-calibrating system does not require the use of an OTA chamber setup, reducing costs. do.

[0028] In 3GPP or IEEE wireless systems, 64QAM, 256QAM, or Higher order modulation schemes such as OFDM with 1024QAM are used. This type of modulation is To avoid high EVM (Error Vector Magnitude), the power amplifier must operate in its linear region. In a phased array antenna, the objective is to generate a precise antenna pattern, and To avoid power amplifier nonlinearities (driving the PA with a suitable backoff), It is desirable to monitor the output power from the IC in the tena element. - The signal passes through many stages of active devices before reaching the amplifier, Each stage contributes some error to the amplifier gain. Therefore, it is important to adjust the signal level to the appropriate power level. It is desirable to measure the output power and adjust the gain to maintain the amplifier operating point.

[0029] Figure 7 shows the power amplifier performance at various power amplifier classes and their appropriate back-off operating points. The average power consumption of a power amplifier (if it is not a Class A amplifier) ​​is Note that this depends on the operating level (signal level). When there is no input signal, the power As the input signal increases, the PA bias current also decreases. The follow current is the average operating bias current minus the quiescent current. As shown in Figure 7, , small signals do not induce current conduction, and stronger signals produce high current conduction duty cycles. .

[0030] The proposed invention is based on the measurement of the PA follow current at the appropriate back-off operating point of the PA: Implementing a power detector in a preferred embodiment of a CMOS class AB PA When the output power is backed off by about 6 to 7 dB from P1 dB, the follow current is It can be seen that the output power level is accurately reflected regardless of the input voltage and temperature.

[0031] FIG. 8 illustrates a phased array antenna for self-calibrating output power in accordance with another embodiment. In the output power measurement, the following current is measured using the The same bias current measurement system is applied. Step 8: Turn off all active circuits except for the active circuit in the selected signal path. At 02, a signal of known signal level is input and the PA follow-on current is measured. It is usually CW (continuous wave) and the input signal level is determined by the most accurate follow current (i.e., process or supply voltage). The output power level is selected to correspond to the minimum dynamic fluctuation due to pressure changes. First, the quiescent current is measured while the input is off, and then the follow-on current ( (i.e., the operating bias current with an input signal minus the quiescent current) In step 803, the bias current of the PA is measured when the signal is turned on. Adjust the amplifier gain of the selected signal path leading to that power amplifier until the desired follow current is achieved. Adjust the variable gain amplifier in each path to correct the error ΔG. Step 80 4, all PAs in the system are connected to the same signal path until they reach the same follow current (Pout). Repeat the same procedure for all power amplifiers.

[0032] FIG. 9 illustrates an output power self-calibration system for a phased array antenna according to another embodiment. 9 shows an embodiment of the output power self-calibration system 900. The output power self-calibration system 900 is similar to the bias voltage shown in FIG. Similar to the current self-calibrating system 600, it has three different supply voltages for operation and four Additional regulators to calibrate the circuit (system under test) divided into power domains For example, the regulator and switch are implemented. allows separate calibration for different supply voltages of 1 volt, 1.7 volt, and 3.3 volt. To reduce power consumption, for example by controlling it with a regulator and a switch. Additionally, the four power domains can also be calibrated individually. During calibration, the All circuits except the circuit are turned off. For each circuit, 1) measure the output power Pout, and 2) ) measure the gain G = Pout / Pin, and 3) measure the gain G until the desired follow current of the power amplifier is achieved. , the error ΔG is corrected by adjusting the variable gain of the power amplifier of the selected path.

[0033] By monitoring the 1.7v PA follow current, the entire signal chain can be calibrated. At the center frequency, the gain / power becomes more flat, so the gain over process and temperature / To minimize power sensitivity, all stages need to be tuned to the correct center frequency. The frequency tuning procedure is accurate enough to limit the error to less than 1 / 2 LSB of 0.375 dB. Calibration is performed by first fine-tuning the center frequencies of all stages to the desired frequency, then This can be achieved by adjusting the gain to reach the desired 1.7v PA follow current. In conclusion, above 6dbm, the error is 0.37 across the process corner. The error is less than 1 / 2LSB of 5dBm. The error over temperature (30°C to 80°C) is 1.5LSB. B, and is due to the center frequency shift due to temperature. If you operate at the center frequency, the error is Re-simulation with temperature at the corresponding center frequency This reduces temperature sensitivity to an acceptable level by operating only at the center frequency. It has been demonstrated that the calibration procedure can be performed at different signal frequencies and the calibration The settings can be stored in the µC and loaded depending on which signal frequency is selected. can.

[0034] FIG. 10 illustrates an active area on an RFIC of a phased array antenna according to another embodiment. 10 is a flowchart of a method for self-calibrating the bias current of a circuit. In this case, the calibration circuit powers off all active circuits and the power amplifier of the RFIC. In step 1002, the calibration circuit powers off the active circuitry of the RFIC being calibrated. In step 1003, the calibration circuit ,measures the bias current of the active circuit and adjusts the bias current to a predetermined level during calibration In step 1004, the calibration circuit performs the following for each active circuit of the RFIC: Repeat the bias current calibration for all RFICs in the phased array antenna. .

[0035] FIG. 11 illustrates a power amplifier on an RFIC of a phased array antenna according to another embodiment. 11 is a flowchart of a method for self-calibrating the output power of a power amplifier. In step 1101, The calibration circuit powers off all active circuits on the RFIC and the power amplifier, and Power on the amplifier and the corresponding signal path of the RFIC under calibration leading to the power amplifier In step 1102, the calibration circuit provides an input signal having a predetermined signal level. In step 1103, the calibration circuit measures the follow current of the power amplifier being calibrated. The amplifier gain and output of the corresponding signal path leading to the power amplifier are adjusted until the desired follow-on current of the power amplifier is reached. In step 1104, the calibration circuit adjusts the output power to achieve a predetermined signal level. For each power amplifier and corresponding signal path in the RFIC, the same input signal is used, and Repeat the output power calibration for all RFICs in the phased array antenna.

[0036] Although the present invention has been described in connection with several specific embodiments for purposes of illustration, However, the present invention is not limited thereto. Various modifications of the various features of the described embodiments may be made without departing from the scope of the present invention. Adaptations and combinations may be performed.

Claims

1. A method for self-calibration of radio frequency integrated circuits (RFICs) in a phased array antenna. So, powering off all active circuits and power amplifiers on the RFIC; and, The active circuit of the RFIC being calibrated is powered on, and the current consumption of the active circuit is monitoring the Measure the bias current of the active circuit and adjust the bias current to a predetermined level during calibration. adjusting the Each active circuit of the RFIC and all of the active circuits in the phased array antenna and repeating the calibration of the bias current for an RFIC.

2. An analog-to-digital converter (ADC) is used to measure the voltage across the precision resistor R.

2. The method of claim 1, wherein the bias current is measured by a μC using a

3. The μC cycles the current digital-to-analog converter (DAC) until the desired bias current is reached.

3. The method of claim 2, wherein the temperature is adjusted to 100° C.

4. Each active circuit within the RFIC can be turned on or off under the control of the μC. The method of claim 1 .

5. During the bias current measurement, the main voltage source is turned off and the auxiliary voltage source is turned on.

1. The method according to claim 1.

6. A method for self-calibration of radio frequency integrated circuits (RFICs) in a phased array antenna. So, All active circuits and power amplifiers on the RFIC are powered off, and power on the power amplifier and the corresponding signal path leading to the power amplifier of the RFIC being calibrated. and An input signal having a predetermined signal level is input and the follow current of the power amplifier being calibrated is measured. and The amplifier gain and the power amplifier output are adjusted until the desired follow current of the power amplifier is reached. adjusting the output power of the corresponding signal path; Using the same input signal having the predetermined signal level, each power amplifier and the RF for the corresponding signal path of the IC and for all RFICs in the phased array antenna. and repeating the calibration of the output power for the

7. The step of measuring the follow current of the power amplifier is performed while the input signal is turned off. The quiescent current is measured while the input signal is on, and then the bias voltage is measured when the input signal is turned on. The method of claim 6, further comprising measuring the flow.

8. 8. The method of claim 7, wherein the follow current is equal to the average bias current minus the quiescent current. 。

9. The follow current is measured at a predetermined back-off operating point of the power amplifier corresponding to high accuracy. The method of claim 6 .

10. The desired follow current reflects the output power level at the predetermined back-off operating point. The method of claim 9, wherein

11. A phased array antenna including a plurality of radio frequency integrated circuits (RFICs), each RFIC is A plurality of active circuits and power amplifiers that are initially powered off, The active circuits of the RFIC in the An amplifier and A measurement circuit including a μC for monitoring the current consumption of the active circuit, the μC comprising: measuring the bias current of the active circuit and adjusting the bias current during calibration; a constant circuit; Repeating the calibration of the bias current for each active circuit of the RFIC. and a number of regulators and switches.

12. The μC uses an analog-to-digital converter ( 12. The phased array of claim 11, wherein the bias current is measured using an ADC. antenna.

13. The μC cycles the current digital-to-analog converter (DA) until the desired bias current is reached. The phased array antenna of claim 12, wherein the phased array antenna further comprises:

14. Each active circuit within the RFIC can be turned on or off under the control of the μC. The phased array antenna according to claim 11 .

15. During the bias current measurement, the main voltage source is turned off and the auxiliary voltage source is turned on. Item 12. The phased array antenna according to item 11.

16. Each RFIC: an input node receiving an input signal having a predetermined signal level, an input node at which the follow current of the power amplifier of the IC is measured; an output node that outputs the output power of a selected signal path to the power amplifier; The output power is adjusted to achieve a desired follow current by adjusting the gain of the selected signal path. and the calibration of the output power is adjusted for each power amplifier of the RFIC. and an output node, the output node being repeated in a sequential manner. Antenna.

17. The step of measuring the follow current of the power amplifier is performed while the input signal is turned off. The quiescent current is measured while the input signal is on, and then the bias voltage is measured when the input signal is turned on. The phased array antenna of claim 16, further comprising measuring current.

18. 18. The method of claim 17, wherein the follow current is equal to the average bias current minus the quiescent current. Phased array antenna.

19. 17. The power amplifier of claim 16, wherein the follow current is measured at a back-off operating point of the power amplifier. Phased array antenna.

20. The desired follow current reflects the output power level at the back-off operating point.

20. The phased array antenna of claim 19.

Images