RU30047U1 - Exciter with pseudo-random tuning of the operating frequency - Google Patents

Description

Pseudorandom Reorganization

OPERATING FREQUENCY1

The utility model relates to the field of radio communications, can be used in radio systems designed to receive and generate signals with pseudo-random tuning of the operating frequency (MHF),

At present, exciters with frequency hopping are known, in which two synthesizers are used as a local oscillator: one for the receiver, the other for the pathogen (see the Exciter of the product "Tuf E - PRMV ITNYA.468123.061).

In the product "Aqueduct MKD" Transportable VHF radio stations Ed. YOU 1996 UDC.621.396.7 use one channel synthesizer as a local oscillator for both the receiver and the pathogen.

But for those and other excitatory receptors, there is a drawback determined by the peculiarity of a one-loop synthesizer with a phase locked loop (PLL): a sufficiently long transition time from one frequency to another.

For the effective operation of systems with frequency hopping, a sufficiently large number of operating frequencies is necessary - N.

N AlA,

A / where f2 - f 1 - the range of frequencies allocated to the system, it is limited;

And f is the pitch of the frequency grid.

The maximum comparison frequency for a single-loop synthesizer cannot be greater than the step of the frequency grid Af. Frequency tuning time is determined by the formula:

 (lQ-b50) (104-5Q) -JV

 A / - l;

Tper. grows linearly with increasing N. As a result of increasing N, the tuning time increases. You can enter the loss factor:

K lane n - ;; g

where TCK is the jump time.

The loss factor determines the loss of bandwidth of the radio channel due to the incomplete use of the temporary resource. Losses are due to the fact that, at a fixed transmitter power, the total energy of the emitted signal decreases (1-Kp) times, or, to preserve the information transfer rate, the channel speed must be increased 1 / (1-Kp) times, which will lead to a corresponding loss of noise immunity ,

There are direct synthesis synthesizers with a relatively fast transition compared to single-loop PLL synthesizers, but they have a limited upper frequency and insufficient spectrum quality to fulfill the requirements for radio receivers.

The closest to the proposed one is the exciter, developed by order of the "Aqueduct MKD ITNYA, 464511.042" Transportable VHF radio stations, Publishing House, VAS 1996, UDC, 621,396.7

In Fig, 1 shows a diagram of the exciter - prototype, where the following notation is introduced:

1- high frequency amplifier (UHF) with a frequency converter;

2-channel synthesizer with PLL loop;

3- exciter (transmitter signal amplifier), exciter with pseudo-random tuning of the operating frequency

depicted in FIG. 1 has the following functional relationships.

The inputs of all blocks 1,2,3 are given control signals. One of the inputs of UHF 1 is the input of the receiver, the output of UHF1 is the output of the intermediate frequency (IF). A subcarrier frequency is supplied to one of the inputs of the exciter 3, the output of the exciter 3 is the output of the exciter. One of the inputs of the channel synthesizer with a FANCH 2 loop is an input for the reference frequency. The output of the channel synthesizer 2 is connected to the corresponding inputs of the UHF 1 and pathogen 2.

The prototype device shown in FIG. 1 as follows.

But the impulse of the perestroika begins the restructuring of the synthesizers, after the time of the restructuring of the synthesizers Tper, they are ready to provide a mode of receiving or transmitting a signal.

For the prototype, a significant drawback is the low speed of the transition from one frequency to another and, as a result, low noise immunity and limited speed jumps.

To eliminate this drawback, an SHTRCH exciter containing UHF with a frequency converter, the output of which is the IF output, a channel synthesizer with a fanch loop and an exciter whose output is the device output, a second channel synthesizer with a fanch loop and a block of high-frequency (HF) keys are introduced. The outputs of the first and second channel synthesizers are connected to the first and second inputs of the RF key block, the third input of which is the control, the outputs of the RF key block are connected to the inputs of the UHF and the exciter, respectively.

The proposed HLF excitator is shown in FIG. 2, where the notation is introduced.

1 - high frequency amplifier (UHF) with a frequency converter; 2, 3 - the first and second channel synthesizers with a FANCH loop;

4- block RF keys;

The scheme of the proposed exciter is shown in figure 2 and has the following functional relationships.

The inputs of all blocks 1,2, 5 are fed control signals. One of the inputs of UHF 1 is the input of the receiver, the other input of UHF 1 is connected to the RF key block 4. The output of UHF 1 is the output of the inverter. A subcarrier frequency is supplied to one of the inputs of the exciter 5, its other input is connected to the output of the RF key block 4. The inputs of the RF key block 4 are connected to the outputs of the channel synthesizers 2 and 3, at the inputs of which the reference frequency is supplied.

The exciter shown in FIG. 2 as follows.

According to the tuning pulse, the UHF filters and / or the exciter, the RF key block and one of the synthesizers are tuned, while the other synthesizer continues to work. The switching time of the RF key block is less than a microsecond.

Thus, the advantage of the prototype is retained: one synthesizer per receiver and exciter, and, in addition, the proposed excitation exciter reduces the tuning time, since it is determined by the switching time of the RF keys, which is an order of magnitude lower than that of a single-loop channel synthesizer with a phase-locked loop ( FUNCH).

The essence of the ongoing process of switching from one frequency to another in the prototype and the inventive receiving device can be demonstrated by the diagrams depicted in Fig.Z. On Fig.3 shows the process of transition from one frequency to another in the prototype. In Fig. 3 shows the process of transition from one frequency to another in the proposed exciter.

For the prototype (Fig. 3), the loss coefficient is determined by K.

In the claimed exciter (Fig. 3), the loss coefficient is determined by K. Moreover, as can be seen from the diagrams, tp is much larger. The exciter with frequency hopping is used as in simplex mode:

Yes, either the receiver or the pathogen works. In this case, fnn f of the subcarrier. It is possible to use such a receiver exciter in duplex mode, when both the receiver and the exciter are working. In this mode, f pch differs from f subcarrier by ± the frequency of duplex spacing.

Particularly significant gain from the use of the proposed exciter technique is obtained at higher speeds of tuning from one frequency to another, because on the basis of the loss coefficient formula for the prototype, it is necessary that the tuning time of the synthesizer tp is much less than TCK, and for the claimed value, the tp tp is 5 Tek

5

Patent holder - Voronezh Research Institute of Communications

Chief Engineer A.V. Kalinin

Claims (1)

A receiving exciter with pseudo-random tuning of the operating frequency (PFC), comprising a high-frequency amplifier (UHF) with a frequency converter, the output of which is an intermediate frequency output, a channel synthesizer with a phase-locked loop (PLL) and an exciter whose output is the output of the device, characterized in that a second channel synthesizer with a PLL loop and a block of high-frequency (HF) keys are introduced, the outputs of the first and second channel synthesizers are connected to the first and second inputs of the RF key block, the third whose input is control, the outputs of the RF key block are connected to the inputs of the UHF and the pathogen, respectively.