JPS60248026A - Receiver - Google Patents

Abstract

PURPOSE:To attain the operation as a diversity receiver by using an indenpendent local oscillator when two receivers receive different frequencies respectively and using any local oscillator when they receive the identical frequency in common. CONSTITUTION:Two reception systems are provided and in case of the operation such as searching of a station broadcasting the same content or a traffic information station, a control circuit 10 selects the position A to a changeover circuit 14 to stop the operation of a multi-path detection and comparison circuit 12 thereby allowing a changeover circuit 13 to select the position A. Thus, a reception system 9a acts as a system receiving a frequency and a reception system 9b acts as a system searching an in-band signal with a prescribed purpose. In this case, the reception systems 9a, 9b are independent. On the other hand, in case of the operation as a diversity receiver, the circuit 10 allows the circuit 14 to be connected to the position B, an output of a local oscillating circuit 6a of the reception system 9a is inputted to a mixng circuit 4b of the reception system 9b and the reception systems 9a, 9b receives the same frequency. The circuit 12 is actuated at the same time to allow the circuit 13 to select a frequency with less multi-path disturbance and the sound is outputted from a speaker 16.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a receiver with two receiving yarn gaps.

[Background of the invention]

Receivers with two receivers for searching for content stations and traffic information stations are known. Figure 2 is a front diagram showing the configuration of such a receiver.In the figure, 1 is the antenna, 2 is the distributor, 3a, 3b are the local frequency amplifier circuits, 4a, 4
b is a mixing circuit, 5a and 5b are intermediate frequency width circuits, 6a
,6b&! Local excavation circuit, 7a, 7b are PLLu tract, 8
a, 8h are low-pass filter circuits, 9a is a first receiving system, 9b is a second receiving system, and 10 is a control circuit.

Such a receiver has one frequency r, for example a receiving thread 9a.
During reception, the receiving system 9b searches within the band for a predetermined purpose.

Theoretically, if this operation is stopped, the two receiving threads 9a and 9b receive the same frequency, and a multipath detection, comparison and switching circuit is added, it can be operated as a diversity receiver. It becomes possible.

However, in reality, there are variations in the characteristics of the variable capacitance diode elements used in the nine local oscillation circuits 6a and 6b.
It is impossible for the two local oscillation frequencies to completely match, and the difference between them becomes a beat, which is disadvantageous in that it interferes with the audio output.

[Purpose of the invention]

An object of the present invention is to enable a receiver equipped with two receiving systems to operate as a guivacity receiver when those functions are stopped for the purpose of preserving data for each station or traffic information station. It is possible to provide a receiver.

[Summary of the invention]

In order to achieve the above object, the receiver according to the present invention uses independent local oscillator cans when receiving two different frequencies, and uses a switching circuit when receiving the same frequency. The gist is that either one of the local oscillation circuits can be shared.

Hereinafter, the present invention will be explained in more detail using an embodiment with reference to the drawings, but these are merely illustrative and various forms and improvements may be made without going beyond the scope of the present invention. Of course.

[Embodiments of the invention]

FIG. 1 is a block diagram of a receiver according to the present invention, and the reference numbers common to those in FIG. 9b antenna.

11a and llb are detection circuits, 12 is multipath detection,
Comparison circuit, 13 and 14 are switching circuits, 15 is a low frequency amplification circuit, and 16f SB power.

The receiver shown in FIG. 1 operates as shown.

In the case of an operation such as searching for the same content or communication information station, the control circuit 10 outputs an output to the switching circuit 141C to select the A side, and the multipath detection and comparison circuit 12 outputs the output to select the A side. The operation is stopped and the switching circuit 13 is made to select the A side. Therefore, the receiving thread 9a operates as a system for receiving a certain frequency, and the receiving thread 9b operates as a fixed thread for the purpose of in-band recording. In this case, receiving thread 9a
and 9b are independent of each other.

In the case of operation as a diversity receiver, the control circuit 10 causes the switching circuit 12 to select the B side, operates the multipath detection/comparison circuit 12, and operates the switching circuit 13. Output to select the receiving Q side with less multipath interference. Therefore, the output of the local oscillation circuit 6a of the receiving thread 9a is input to the mixing circuit 4b of the receiving thread 9b, and the receiving threads 9a and 9b receive the same frequency, and the hook sound with less multipath. VCI:c is output from the speaker 16 by following the P-pin switching circuit 13 and the low frequency amplification circuit 15.In this case, 9: signal line 9h
K follows the PLL control of the receiving thread 9a. In addition.

At this time, in order to stop the oscillation of the local oscillation circuit 6b,
The supply type 8: the oscillation frequency is 1' or the oscillation frequency is the local oscillation circuit 6a), and the reception line 9a.
The control circuit 10 must output the necessary data to the PLL circuit 7 so that Tf is near the beginning of the receiving frequency of 9b and 9b.

〔Effect of the invention〕

As explained above, according to the present invention, in two receivers equipped with two receiving frequencies, it is possible to receive two different frequencies individually and receive the same frequency.
Therefore, the increase in cost associated with providing two reception lines can be relatively reduced by diversifying the functions.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a receiver according to the present invention;
Figure 2 shows the tflt of a conventional receiver with two receiving threads.
It is a block diagram showing rltw. 1, la, lh...antenna, 2...distributor, 3a
. 3b...high frequency amplification circuit, 4a, 4b...mixing circuit. 5a, 5b... intermediate frequency amplification circuit, 6a, 6b...
Local oscillation times 5.7a, 7h-PLL times %, 8a,
8b...Low pass filter circuit, 9a...First receiving g string. 9b...Second receiving thread, 10...Control circuit, lla
, 111>...detection circuit, 12...multipath detection, comparison circuit, 13°I4...9J switching circuit, 15...
・Low frequency amplification circuit. Patent applicant Tararion Co., Ltd.

Claims (1)

[Claims] In a receiver equipped with two receiving systems, when receiving two frequencies that are different from each other, independent local oscillator cans are used, and when receiving the same frequency, a switching circuit is used to select either one. One of the local oscillation generators can be used in common with a special enemy and a receiver.