RU56089U1 - ANTENNA CONSENTING DEVICE - Google Patents

Abstract

The utility model relates to communication technology and can be used in wide-band radio transmitters to compensate for deviations of the input impedance of the antenna from a value that ensures the optimal operation of the power amplifier of the radio transmitter. The objective of the utility model is to significantly reduce setup time. The antenna matching device contains a matching circuit formed by elements of four reactivity stores, a first switch connected by the first output to the input of the matching circuit, an attenuator connected by an input to the second output of the first switch, a current transformer connected by the first output of the primary winding to the first output of the attenuator, a phase discriminator connected by a voltage input to the second output of the attenuator, and the input and output of the current winding is connected respectively to the second output of the primary windings of the current transformer and the second input of the first switch, a microcontroller connected by the outputs of the parallel interface to the corresponding control inputs of the first switch and the matching circuit, in which the first input of the first switch and the output of the matching circuit are the RF input and RF output of the device, and the serial interface port of the microcontroller is remote control port of the device, introduced a calibration resistor connected to the third output of the first switch the second and second logarithmic amplifiers connected by inputs respectively to the first output of the attenuator and to the output of the current transformer, the first and second amplitude detectors connected by inputs respectively to the outputs of the logarithmic amplifiers, the second switch connected by the corresponding signal inputs to the output of the phase discriminator, the outputs of the first and second amplitude detectors and to the output of the phase detector, and the control inputs connected to

the corresponding outputs of the parallel interface of the microcontroller, and the analog-to-digital converter connected by an analog input to the output of the second switch, and the digital outputs connected to the corresponding inputs of the parallel interface of the microcontroller, logarithmic amplifiers, amplitude and phase detectors, the second switch, the analog-to-digital converter and the controller are elements of two large integrated circuits.

Description

The invention relates to communication technology and can be used in wide-band radio transmitters to compensate for deviations of the input impedance of the antenna from a value that ensures the optimal operation of the radio transmitter power amplifier.

A known antenna matching device [1], containing a matching circuit formed by elements of four reactivity stores, an attenuator, a block of sensors of discriminators for monitoring the mismatch characteristics, a switch and a microcontroller, the input of the matching circuit being connected through the switch to the RF input of the device or directly or through a series of attenuators and a block of discriminating sensors, information outputs of the discriminating sensors are connected to the corresponding inputs of the parallel interface the micros of the microcontroller, the control inputs of the matching circuit (control inputs of the reactivity stores) and the control input of the switch connected to the corresponding outputs of the parallel interface of the microcontroller, the output of the matching circuit is the RF output of the device, and the serial port of the microcontroller is the remote control port of the device. The block of discriminating sensors includes:

Z sensor (Z is the module of the complex input resistance), which determines the sign of the difference in amplitudes of two signals proportional to the voltage and current at the input of the matching circuit, respectively. The indicated difference is positive if Z> R ₀ , (R ₀ is the optimal load of the power amplifier of the radio transmitter);

sensor φ (φ is the phase of the complex input resistance), which determines the sign of the phase shift of signals proportional to the voltage and current at the input

matching circuit. The sign of the phase shift is positive if the complex input impedance is inductive, and negative if the input impedance is capacitive;

the KBV sensor, which determines the sign of the difference in the amplitudes of two signals obtained by summing a signal proportional to the voltage at the input of the matching circuit, respectively, with signals proportional to the current at the input of the matching circuit and 180 degrees out of phase with respect to each other.

The indicated difference is positive if it is not less than a certain value C, which is the setting criterion.

In all of the above sensors, to obtain a signal proportional to the current at the input of the matching circuit, a measuring current transformer is used, connected by the primary winding in series with the matching circuit.

The device is tuned to a given operating frequency in the following sequence.

First, when the reactances of the matching circuit are turned off, the antenna input through the sensor discriminator block for a short time T _mouth , sufficient to establish the sensor readings, receives a test signal, which is an unmodulated oscillation with a frequency f _p (T _{mouth also} includes the time to establish the level test signal).

With negative readings of the KBM sensor, depending on the readings of the Z and φ sensors in the absence of a test signal, the minimum discrepancies of one of the four reactivity magazines of the matching circuit are turned on for a time T _switch , after which the test signal is again sent and the sensor readings are checked. If the readings of the sensors have not changed, the next discrete is connected in the same reactivity store. The procedure for switching the discreteness of this reactivity store with monitoring of the sensor readings is carried out until the positive readings of the KBM sensor are obtained,

indicating the completion of the setting, or before changing the readings of the sensors Z and φ. In accordance with the new readings of the Z and φ sensors, the next reactivity store is selected and the procedure for switching its discrete described above is performed.

Other antenna matching devices are also known [2, 3, 4], similar in structure and operation algorithm to the device described above selected as a prototype.

The disadvantage of the matching device under consideration is the long setup time for the matching circuit due to the sequential (sequential) set of small increments of the required values of the reactivities that form the circuit, as well as due to the long switching time of discrete in reactance stores.

The objective of the utility model is to significantly reduce setup time.

To do this, in an antenna matching device containing a matching circuit formed by elements of four reactivity stores, a first switch connected to the input of the matching circuit by the first output, an attenuator connected to the second output of the first switch by a current transformer, and a current transformer connected by the first output of the primary winding to the first output attenuator, phase discriminator connected by a voltage input to the second output of the attenuator, and the input and output of the current winding to the second output of the trans primary the current and the second input of the first switch, respectively, the microcontroller connected by the outputs of the parallel interface to the corresponding control inputs of the first switch and the matching circuit, in which the first input of the first switch and the output of the matching circuit are the RF input and RF output of the device, and the serial interface port of the microcontroller is a remote control port of the device, a calibration resistor connected to the third output of the first

the switch, the first and second logarithmic amplifiers connected by inputs respectively to the first output of the attenuator and the output of the current transformer, the first and second amplitude detectors connected by inputs respectively to the outputs of the logarithmic amplifiers, a phase detector connected by the first and second inputs respectively to the outputs of the logarithmic amplifiers, the second a switch connected by corresponding signal inputs to the outputs of the phase discriminator, amplitude and phase detectors, and the control inputs to the corresponding outputs of the parallel interface of the microcontroller, and the analog-to-digital converter connected by an analog input to the output of the second switch, and by the digital outputs to the corresponding inputs of the parallel interface of the microcontroller.

The block diagram of the connected device is shown in figure 1. The device contains a matching circuit 11 formed by elements of four reactivity magazines, a first switch 4 connected by a first output to the input of a matching circuit, an attenuator 2 connected by an input to the second output of the first switch, a current transformer 6 connected by a first output of the primary winding to the first output of the attenuator, a discriminator phase 5, connected by a voltage input to the second output of the attenuator, and the input and output of the current winding to the second output of the primary winding of the current transformer and the second input to the first switch, respectively, a calibration resistor 12 connected to the third output of the first switch, the first 1 and second 13 logarithmic amplifiers connected by inputs to the first output of the attenuator and to the output of the current transformer, the first 3 and second 14 amplitude detectors connected by inputs to the first output of the attenuator and the output of the current transformer, the first 3 and second 14 amplitude detectors connected by inputs to the outputs of the phase discriminator

the first and second amplitude detectors and the output of the phase detector, an analog-to-digital converter 9, connected by an analog input to the output of the second switch 8, a microcontroller 10 connected by the corresponding inputs of the parallel interface to the phase discriminator output and the digital outputs of the analog-to-digital converter, and the corresponding outputs of the parallel interface to the control inputs of the first and second switch and the matching circuit, and the first input of the first switch and the output of the matching circuit are respectively, the RF input and RF output of the device, and the serial interface port of the microcontroller is the remote control port of the device.

The device is tuned to a given operating frequency in the following sequence.

Initially, the initial values of the characteristics of the input impedance of the antenna are determined. To do this, the calibration resistor 12 or the input of the matching circuit 11, which is connected directly to the antenna input for this time, are alternately connected to the RF input of the device through the attenuator 2, current transformer 6, and phase 5 discriminator, and when the test signal is applied to the RF input, the levels are counted in turn the signals at the outputs of the amplitude detectors 3 and 14 (proportional to the logarithm of the amplitude of the voltage and current at the calibration resistor and at the input of the antenna), the signal at the output of the phase detector 7 (proportional to tional shift of current and voltage at the antenna input phases) and the signal at the output of the phase discriminator 5 (corresponding to the current phase shift sign and voltage at the antenna input). The calibration resistor is disconnected and the input of the matching circuit is connected in the absence of a test signal.

All samples are digitized using an analog-to-digital converter 9 and stored in the microcontroller 10.

The obtained samples are used to calculate the values of active Ra and reactive Xa components of the complex input antenna impedance by the formulas

R _a = Z _a cos (φ)

± X _a = Z _a sin (φ)

Z _a = R _k · 10 ^{An + Atk-Ank-At}

_φ = K φ · U φ

Here:

R _k is the resistance of the calibration resistor;

U _φ is the reference signal of the phase detector;

A _n , A _nk - samples of signals corresponding to the voltage at the input of the antenna and the calibration resistor;

A _t , A _tk - samples of signals corresponding to the current at the input of the antenna and in the calibration resistor;

To _φ is the coefficient of proportionality of the phase detector.

The condition for agreement is the fulfillment of the inequality

where

Ro is the optimal load of the power amplifier of the radio transmitter;

With - the minimum allowable value of the KBV load of the power amplifier.

If this inequality is not fulfilled, the necessary values of the reactance resistances of the matching circuit are calculated, and a set of discrete corresponding reactivity stores implementing these resistance values is determined.

If and Xa> 0, coordination is achieved by turning on a series of “shortening” capacitance with resistance in series with the antenna where

f _p is the operating frequency;

С ∂ _i is the capacity of the i-th discrete store of “shortening” capacities.

If and Xa≤0, in series with the antenna, an “extending” inductance with resistance ,

where L∂ _i is the inductance of the i-th discrete store of “lengthening” inductances.

If Ra <C · Ro, Xa> 0 and , “shortening” capacitance and “communication” capacitance, shunting the input of the matching circuit, are used for coordination. In this case, Hook and Xsv are calculated by the formulas Xook = Xa-Ro · cos (φ ₁ ) · sin (φ ₁ ) and Where

С ∂ _i is the capacity of the i-th discrete store of capacities "communication".

If Ra <C · Ro, Xa> 0 and for matching, “lengthening” inductance and “coupling” capacitance with resistances are used

Hoodle = Ro cos (φ ₁ ) sin (φ ₁ ) -Xa, .

If Ra <C · Ro and Xa <0, the resistance Xsv is determined by the formula specified in the previous case, and the resistance Hood is determined by the formula Hood = Xsv + Ro · cos (φ ₁ ) · sin (φ ₁ ).

If , Xa> 0, matching is done by the “lengthening” inductance and the capacitance shunting the antenna input. The resistance Hoodle and Xsh are determined by the formulas

Where

C∂ _i is the capacity of the i-th discrete of the shunt capacitance store.

If and Xa <0, the Hood resistance is determined by the formula specified in the previous case, and the resistance Xw is determined by the formula .

The discrete sets determined from the above calculations are included simultaneously from the corresponding reactivity stores. As a result of setting time T _Setup of the device is defined as a predetermined operating frequency

where

- time to establish the level of the test signal and take samples when connecting a calibration resistor and matching circuit, respectively ;

T _calcul - the time to calculate the necessary values of reactivity in

matching circuit and determining a set of discrete realizing these reactivity values. T ms _calc'd ≤0,3;

- time off calibration resistor and on time discrete, respectively. .

The prototype setup time is defined as

T _setup = N ₁ · T _mouth + N ₁ · T _switch , where:

N ₁ - the number of switching discrete, which is practically within 10-150.

In accordance with the above expressions, the prototype setup time is within 0.4 ... 6 seconds, and the setup time of the proposed device does not exceed 81 ms, which indicates the achievement of the goal.

In order to improve the accuracy and reliability of the device and the accuracy of measuring the characteristics of the antenna, the proposed utility model uses large integrated circuits (LSI) of the type AD8302 from Analog Devices [5] and HD64F2633TE from Renesas Technology [6].

LSI AD8302 includes two logarithmic amplifiers with amplitude detectors and a phase detector.

LSI HD64F2633TE includes a multiplexer (switch), analog-to-digital converters, and the controller itself.

Information sources.

1. Operation manual for the AnSU-1000P unit, ONIIP, Omsk, 2005 (prototype).

2. Technical description of the ACS-Bk unit, NPP “Flight”, N.Novgorod, 2001

3. Repair Manual 6045.5874.62.02 Antenna Tuning Unit FK 2100, f. Rohde & Schwarz, 1995

4. Mantenimiento DEL RF-5800H-MP, f. Harris, 2001

5. AD8302 Data Sheets, Rev. 0, Analog Devices, Inc., 2002

Claims (2)

1. Antenna matching device containing a matching circuit formed by elements of four reactivity magazines, a first switch connected by a first output to an input of a matching circuit, an attenuator connected by an input to a second output of a first switch, a current transformer connected by a first output of a primary winding to a first output of an attenuator , the phase discriminator connected by the voltage input to the second output of the attenuator, and the input and output of the current winding is connected respectively to the second output of the primary the current winding of the current transformer and the second input of the first switch, a microcontroller connected to the outputs of the parallel interface to the corresponding control inputs of the first switch and the matching circuit, in which the first input of the first switch and the output of the matching circuit are the RF input and RF output of the device, and the serial interface port of the microcontroller is a remote control port of the device, characterized in that a calibration resistor connected to the third the output of the first switch, the first and second logarithmic amplifiers connected by the inputs respectively to the first output of the attenuator and the output of the current transformer, the first and second amplitude detectors connected by the inputs respectively to the outputs of the logarithmic amplifiers, the second switch connected by the corresponding signal inputs to the output of the phase discriminator, the outputs the first and second amplitude detectors and to the output of the phase detector, and the control inputs are connected to the corresponding outputs in parallel microcontroller interface, and an analog-to-digital converter connected by an analog input to the output of the second switch, and connected by digital outputs to the corresponding inputs of the parallel interface of the microcontroller. 2. The antenna matching device according to claim 1, characterized in that the logarithmic amplifiers, amplitude and phase detectors, a second switch, an analog-to-digital converter, and a controller are elements of two large integrated circuits.