RU2809995C1 - Multichannel ultra-wideband radio receiver - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: used in wideband ultra-high frequency (UHF) radio receiving devices, in particular in ultra-wideband aviation electronic monitoring systems that have restrictions on weight and size characteristics and power consumption. In a multi-channel ultra-wideband radio receiving device, the antenna is made in the form of a receiving antenna system, in each receiving channel the preselector consists of an active k-channel frequency-selective splitter and k bandpass filters, the operating frequency converter to an intermediate frequency in each channel is made in the form of k quadrature demodulators, the generator is made in the form of a local oscillator module that forms a grid of k frequencies. In the phase shifter module, each j-th frequency component of the heterodyne frequency grid is divided in-phase using a common-mode power divider into n components, for which an individual phase shift is added. The antenna system is a multibase non-equidistant n-channel phase interferometer.

EFFECT: increasing throughput and reducing response time to new threats, avoiding missing threats and simultaneously suppressing targets across the entire operating frequency range, and minimizing hardware costs by expanding the instantaneous swath.

1 cl, 1 dwg

Description

The invention relates to the field of radio engineering and can be used in wideband ultra-high frequency (microwave) radio receiving devices, in particular in ultra-wideband aviation electronic monitoring systems that have restrictions on weight and size characteristics and energy consumption.

Multi-channel receiving devices are known (A.I. Kupriyanov, L.N. Shustov. “Electronic warfare. Fundamentals of theory,” M.: University Book. 2011, pp. 92-97). The operating frequency range of the receiving device is divided by a system of electrical filters into a number of subbands. The transparency bands of the filters are adjacent to each other, and the width of the transparency band of each filter is selected from the condition of the given frequency determination accuracy and the given spectrum width of the received signals. The disadvantages of such a multichannel device include, first of all, the need to use a large number of electrical filters in broadband receiving devices. This leads to a significant increase in size and complexity of the equipment.

Known patent RU 2329598 C1 “Radio receiving device and its variants”, published on 01/27/2016, accepted as a prototype. The prototype, which uses classical methods of increasing the broadband of a radio receiving device by improving microwave radio signal receiver units, increasing the working bandwidth of microwave receiver channels and increasing their number, and using a matrix method for organizing the reception of radio signals in a wide frequency range, has the following disadvantages:

- every pulse of an enemy radar station operating with fast frequency agility (FFA) from pulse to pulse is not detected, and each pulse is not interfered with, which reduces the effectiveness of radar detection;

- an increase in throughput is achieved by a significant, even unacceptable, increase in weight and size characteristics and energy consumption.

The technical result of the claimed invention is to increase throughput and reduce response time to new threats, avoid missing threats and simultaneously suppress targets across the entire operating frequency range, and minimize hardware costs by expanding the instantaneous swath.

To achieve a technical result in a multi-channel ultra-wideband radio receiving device containing an antenna and N receiving channels, each of which consists of a series-connected preselector, an operating frequency converter to an intermediate frequency, the heterodyne input of which is connected to the output of the generator, the antenna is made in the form of a receiving antenna system representing is a multi-base non-equidistant n-channel phase interferometer, in each receiving channel the preselector consists of an active k-channel frequency-selective splitter and k band-pass filters, the operating frequency converter to the intermediate frequency in each channel is made in the form of k quadrature demodulators, the quadrature outputs of which connected to the inputs of the adder of quadrature components, the quadrature outputs of which are the quadrature outputs of the receiving channel, while the generator is made in the form of a local oscillator module that forms a grid of k frequencies, the output of the local oscillator module through a phase shifter module, in which each j-th frequency component of the heterodyne frequency grid in-phase is divided using a common-mode power divider into n components, for which an individual phase shift is added, connected to the heterodyne inputs of the operating frequency converter to an intermediate frequency.

The invention is illustrated by a block diagram of a multi-channel ultra-wideband radio receiving device shown in the figure.

The following designations are used in the figure:

1. Receiving antenna system (PRM_AS).

2. Receiving antennas (from A ₁ to A _n ).

3. Radio receiving device (RPU).

4. Active k channel frequency-selective splitters (from ACIR ₁ to ACIR _n ).

5. Bandpass filters (from PPF ₁ to PPF _k ).

6. Quadrature demodulators (QDM _ij - QDM _nk ).

7. Common-mode power adders (from SUM ₁ to SUM _n ).

8. Phase shifter module (MFSM).

9. Phase shifters (from Δϕ ₁ to Δϕ _n ).

10. Common-mode power dividers (from SDM ₁ to SDM _k ).

11. Local oscillator module (MGET).

Signals from radio electronic equipment (RES) present on the air are received by the receiving antenna system (PRM_AS), which is a multi-base non-equidistant n-channel phase interferometer. Consequently, in PRM_AS there are n receiving antennas (A ₁ - A _n ).

The RES signals received in each channel are sent to the RPU, to the preselector, which consists of an active k-channel frequency-selective splitter (AFS) and k band-pass filters (PPF ₁ - PPF _k ).

ACIR provides compensation for losses arising from signal branching and simultaneous parallel operation of all PPFs. Due to this, the operation of the RPU is achieved immediately in the entire range of operating frequencies, that is, the instantaneous span is equal to the range of operating frequencies and, therefore, reaches its maximum possible value, corresponding to the maximum possible throughput.

In each frequency channel formed by the preselector, each antenna channel using quadrature demodulators (QDM _ij - QDM _nk ), where QDM _ij corresponds to the i-th receiving channel and the j-th frequency channel of the preselector , a quadrature frequency conversion occurs from the corresponding section of the operating frequency range to zero intermediate frequency (IF). At the output of each CDM, two quadrature IF outputs are formed.

To convert frequency to CDM, the local oscillator module (MGET) forms a grid of k simultaneously operating frequencies (f ₁ -f _k ), its own local oscillator frequency for each frequency channel of the preselector, while each local oscillator frequency is tuned to the central frequency of the corresponding PPF. Thus, the number of frequencies k in the heterodyne grid coincides with the number of frequency channels of the preselector or the number of PPFs in each receiving channel of the RPU. The frequency grid with the MGET output is supplied to the phase shifter module (MFVR), where each j-th frequency component of the heterodyne frequency grid in-phase is divided using a common-mode power divider (CPD) into n components, according to the number of receiving channels of the RPU. Then for each i-th component corresponding to the i'-th receiving channel of the RPU , each j-th frequency component of the heterodyne frequency grid corresponding to the j-th frequency channel of the preselector is added with an individual phase shift using a phase shifter Δϕ _i; or phase "color".

The signals of all frequency channels from the outputs of the KDM in each receiving channel are summed separately for each quadrature component by in-phase power adders (SUM ₁ -SUM _n ). In the future, their separation and assignment to a specific local oscillator with which the frequency conversion occurred, and, accordingly, assignment to a specific frequency channel, will be done due to the phase “color” of the heterodyne frequency grid and analysis of the phase distribution at the RPU outputs.

Thus, simultaneous processing of the entire range of operating frequencies, occupying several intermediate frequency (IF) bands, is achieved without increasing the number of parallel signal processing channels.

Let a multi-channel ultra-wideband radio receiving device be a multi-base non-equidistant n-channel phase interferometer, in which the receiving antennas (A ₁ -A _n ) are located on the same line, and the base d _i corresponds to the distance between antennas A ₁ and A _i and is determined by the formula:

d _i =d*(i-1)+Δd*(i-1) ² , where

d and Δd are calculated constants.

Let direction finding be carried out in the angular sector ±β. In this case, the transfer of signals from the operating frequency range is carried out by a heterodyne grid of k simultaneously operating frequencies (f ₁ -f _k ), where each j'-th frequency component of the heterodyne frequency grid f _j in-phase is divided into n components, according to the number of receiving channels of the RPU. In this case, in each i-th receiving channel of the RPU all heterodyne signals arrive with a phase shift (phase “color”), determined by the formula:

r _i =Δr*(i-1), where

Δr is the calculated constant.

Then the measured phase difference between the signal received by the i-th receiving channel of the radio receiver, for a signal with frequency f _c , arriving at an angle to the normal drawn to the line of location of the receiving antennas, is determined by the formula:

, Where

c=3 10 ⁸ m/s - speed of light;

- local oscillator frequency from the heterodyne frequency grid from which the signal frequency was converted to zero IF;

trunk(a) - function of taking the integer part of the number a.

The phase distribution of the received signal over the channels of a radio receiver according to formula (1) is a set of initial data for solving the problem of detecting a signal and measuring its frequency (determining the local oscillator frequency from the heterodyne frequency grid from which the signal frequency was converted to zero IF) and bearing. To solve this problem, it is necessary to calculate the conditional probability of signal reception as a function of the direction of arrival of the signal and the local oscillator frequency, which is essentially a likelihood function defined by the formula:

, Where

β - direction of signal arrival;

ƒ - local oscillator frequency;

w(i, β, ƒ) - support function defined by the formula: .

The likelihood function according to formula (2) is calculated for the entire possible range of changes in the directions of arrival of signals and frequencies of local oscillators. It is advisable to select the discrete change in the direction of signal arrival when calculating the likelihood function to be equal to no more than half of the maximum specified direction finding error, but not less than the value at which the computational process will become unacceptably long. The discrete change in the local oscillator frequency must correspond to the discrete local oscillator grid. The desired values of the direction of signal arrival and the local oscillator frequency are determined by the criterion of the likelihood function exceeding the accepted threshold value.

Claims (1)

A multi-channel ultra-wideband radio receiving device containing an antenna and N receiving channels, each of which consists of a series-connected preselector, an operating frequency converter to an intermediate frequency, the heterodyne input of which is connected to the output of the generator, characterized in that the antenna is made in the form of a receiving antenna system, which is multi-base non-equidistant n-channel phase interferometer, in each receiving channel the preselector consists of an active k-channel frequency-selective splitter and k bandpass filters, the operating frequency converter to intermediate frequency in each channel is made in the form of k quadrature demodulators, the quadrature outputs of which are connected with the inputs of the adder of quadrature components, the quadrature outputs of which are the quadrature outputs of the receiving channel, wherein the generator is made in the form of a local oscillator module that forms a grid of k frequencies, the output of the local oscillator module is through a phase shifter module, in which each j-th frequency component of the heterodyne frequency grid in-phase is divided using a common-mode power divider into n components, for which an individual phase shift is added, connected to the heterodyne inputs of the operating frequency converter to an intermediate frequency.