JPH0265421A - Wireless receiver - Google Patents

Abstract

PURPOSE:To eliminate the difference of local oscillation frequencies and to prevent beat crosstalk to a regenerated voice signal by generating a signal of a local oscillation frequency by the same reference frequency when plural antenna converters are installed. CONSTITUTION:A signal of a reference frequency from a reference oscillator 21 of a receiver main body 20 is distributed by a distributer 24 and fed to antenna converters 30, 40 via terminals 25a, 25b and cables 26a, 26b respectively. The phase of the reference frequency and the phase of the signal of the 1st intermediate frequency of a set multiple to a prescriber divider 33c in advance are compared by the antenna converters 30, 40 and a phase of the signal in a 1st local oscillation frequency is locked. Thus, the difference of each local oscillation frequency is eliminated and the regenerated voice signal is immune to beat crosstalk.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a wireless receiving device used in broadcasting stations, halls, theaters, schools, etc.

BACKGROUND ART FIG. 2 shows a general wireless receiving device using an antenna converter, in which a receiver body 1 is connected to a coaxial cable 2.
They are connected to the antenna converter 3 and the additional antenna converter 4 for space diversity via a12b, respectively.

FIG. 3 shows the configuration of a conventional antenna converter 3.4, in which 5I'i is an antenna that receives a radio signal, 6 is a high frequency amplifier (RF) that amplifies the high frequency signal received by the antenna 5, 7 is a first local oscillator (OSC) that generates a signal at a first local oscillation frequency using a crystal 8;
10 is a mixer unit that mixes the high frequency signal from the high frequency amplification unit 6 and the signal of the first local oscillation frequency from the first local oscillator 7 and converts it into an intermediate frequency; 10 is a first mixer unit that amplifies the signal from the mixer 9; An intermediate frequency amplifier (IF) 11 is a terminal for outputting a signal from the first intermediate frequency amplifying section 10 to the receiver main body 1 via coaxial cables 2a and 2b shown in FIG.

In FIGS. 2 and 3, radio waves from a wireless microphone (not shown) are converted to an intermediate frequency by an antenna converter 3 and an additional antenna converter 4.
It is then converted into an audio signal and played back.

Problems to be Solved by the Invention However, in the above-mentioned conventional wireless receiving device, when a large number of antenna converters 4 are added, the error in each first local oscillation frequency caused by external factors such as ambient temperature and impact causes a difference in beats. Therefore, there is a problem that the reproduced audio signal is affected by beat interference and cannot be received normally.

SUMMARY OF THE INVENTION In view of the above conventional problems, it is an object of the present invention to provide a wireless receiving device that can normally receive signals by making the local oscillation frequencies of individual antenna converters the same.

Means for Solving the Problems In order to achieve the above object, the present invention includes an oscillator that generates a signal at a reference frequency in the receiver body, a circuit that generates a signal at a local oscillation frequency based on the reference frequency, and an antenna. The antenna converter is equipped with a circuit that converts the high frequency signal received through the receiver and the local oscillation frequency into an intermediate frequency signal and outputs the signal to the receiver body.

According to the above configuration, when multiple antenna converters are installed, the present invention generates signals at the local oscillation frequency using the same reference frequency, so there is no difference between the local oscillation frequencies. The audio signal is no longer affected by beat interference and can be received normally.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a wireless receiving device according to the present invention.

In FIG. 1, the upper part of the figure shows the receiver body 2o, the middle part of the figure shows the antenna converter 30, and the lower part of the figure shows the additional antenna converter 40 for space diversity.Since the configurations of the antenna converters 30 and 40 are the same,
The detailed configuration of the additional antenna converter 40 will be omitted.

In the receiver main body 20 shown in the upper part of FIG. 1, 21 is a reference oscillator (OSC) that generates a reference frequency signal using a crystal 213, and 22 is a distributor (HYB) 24 that distributes the reference frequency signal from the reference oscillator 21. , terminal 2sa,
25b to the antenna converter 30.40, and also outputs the first intermediate frequency signal inputted from the antenna converter 30.40 via the coaxial cable 26a126b to the tuner section 23. be.

The tuner unit 23 is an amplifier (RF) 2 that amplifies the first intermediate frequency signal from the antenna converter 30.40.
3a, a second local oscillator (2nd Lo) 23b that generates a signal of the second local oscillation frequency, and a mixer (2nd Lo) that mixes the signal from the amplifier 23a and the second local oscillation frequency and converts it into a signal of the second intermediate frequency. MIX) 23C and a second intermediate frequency amplifier (I) that amplifies the signal from the mixer 23C.
P) 23d and a demodulator (De MOD) that demodulates the signal from the amplifier 23d into an audio signal and outputs it to the terminal 23f.
) 23e.

Antenna converter 3 shown in the middle and bottom rows of Figure 2, respectively.
0.40, 3] and 41 are antennas that receive radio signals, 32.42 are high frequency amplifiers (R, F) that amplify the high frequency signals received by antennas 31 and 41, respectively, and 33.43 is a high frequency amplifier (R, F) that amplifies the high frequency signals received by antennas 31 and 41, respectively. Each PLL generates a signal at a first local oscillation frequency as described later.
Local oscillators, 34 and 44 are respectively high frequency amplifiers 32
．． High frequency signal from 42 and PLL local oscillator 33.43
The mixer section 35.45 mixes the signals of the first local oscillation frequency from the mixer 34.44 and converts them into the first intermediate frequency, and the mixer section 35.45 includes a first intermediate frequency amplifier (IP), 36.45, which amplifies the signal from the mixer 34.44. 46 respectively output the signal from the first intermediate frequency amplifier 35.45 to the terminal 37.47, and output the reference frequency signal from the terminal 37.47 to the PL.
A duplexer (D[JP
).

The PLL local oscillator 33 of the antenna converter 30 includes a frequency divider 33a that divides the reference frequency signal from the duplexer 36 into l/N, and a frequency divider 33a that divides the signal of the reference frequency from the frequency divider 33a and a signal from the prescaler/divider 33C. A phase comparator (φ) 33b that compares the phases of and outputs a phase difference signal, a loop filter (LPF) 33d that converts the phase difference signal from the phase comparator 33b into a voltage according to the voltage, and a loop filter 33
The PLL local oscillator 43 of the additional antenna converter 40 is configured in the same manner.

Next, the operation of the above embodiment will be explained.

In FIG. 1, a reference frequency signal from a reference oscillator 21 of a receiver body 20 is distributed by a distributor 24 and supplied to a antenna T7 bar 930.40 via terminals 25a, 25b and a cable 26a126b, respectively.

In each of the antenna converters 30 and 40, the phase of the reference frequency and the phase of the signal of the first intermediate frequency, which is a multiple set in advance in the prescaler/divider 33C, are compared to lock the phase of the signal of the first local oscillation frequency. Ru.

Therefore, the mixer sections 34.44 of the antenna converter 30.40 mix the high frequency signal from the high frequency amplification section 32.42 and the signal of the same first local oscillation frequency from the L PLL local oscillator 33.43. 1 intermediate frequency, it is possible to output a stable audio signal without beat interference, and even if multiple antenna converters are installed, good reception without dead points can be achieved. .

Further, according to the above embodiment, the antenna converter 30.
Since the 40 PLL local oscillators 33 and 43 each generate the first local oscillation frequency based on the reference frequency from the receiver main body 20, an expensive and highly stable crystal as in the conventional example is not required in each antenna converter 30 and 40. Become.

As described in detail, the present invention includes an oscillator that generates a signal at a reference frequency in the receiver body, a circuit that generates a signal at a local oscillation frequency based on the reference frequency, and a circuit that generates a signal at a local oscillation frequency using the reference frequency. An antenna converter is equipped with a circuit that uses a high frequency signal and this local oscillation frequency to convert it into an intermediate frequency signal and outputs it to the receiver body. Therefore, when multiple antenna converters are installed, the local oscillation frequency is The difference between local oscillation frequencies is eliminated by generating a frequency signal, so that the reproduced audio signal is not subject to beat interference and can be received normally.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating an embodiment of a wireless receiving device according to the present invention. FIG. 2 is a block diagram showing a numerical wireless receiving device, and FIG. 3 is a block diagram showing an antenna converter of a conventional wireless receiving device. 20 ・Receiver body, 21 Reference oscillator, 22...
Crystal, 25a, 25b, cable, 30.40-7
'7 Tena converter, 33.43...PLL local oscillator, 34.44...Mixer section. Name of agent: Patent attorney Shigetaka Awano and one other person

Claims (3)

[Claims] (1) A receiver body including an oscillator that generates a signal at a reference frequency, a circuit that generates a signal at a local oscillation frequency using the reference frequency from the receiver body, and a high-frequency signal received via an antenna and the local oscillator. A wireless receiving device comprising: an antenna converter including a circuit that converts an oscillation frequency into an intermediate frequency signal and outputs the signal to the receiver main body. (2) The wireless receiving device according to claim 1, wherein the local oscillation frequency generation circuit is configured by a PLL circuit. (3) Claim 2, wherein the PLL circuit includes a circuit that selectively sets the generated local oscillation frequency.
Wireless receiving device as described.