JPS63180209A - Receiver - Google Patents

Abstract

PURPOSE:To attain tracking adjustment with electronic circuitry only by using a control voltage line of a variable capacitor in common with a local oscillator and connecting the other to a memory storing an error minimizing data. CONSTITUTION:A control output voltage of a PLL synthesizer 20 is applied with respect to a variable capacitor VC19 for local oscillation to a VC16 in a tuner of a high frequency amplifier stage to apply tuning control. An output signal of a memory 23 storing a data to minimize the tracking error is fed to a control voltage via a D/A converter 24 with respect to a VC15. The output signal of a channel selector 25 is fed to a programmable counter of a synthesizer 20 to apply reception frequency control and used for the address designation of the memory 23 and a data minimizing the tracking error corresponding to the reception frequency is outputted from the memory 23. Thus, the tracking adjustment is applied with electronic circuitry only.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a receiving device used for radio, television, etc.

BACKGROUND OF THE INVENTION In recent years, tracking adjustment in receiving devices has been moving toward automation.

An example of a conventional receiving device will be described below with reference to the drawings.

FIG. 2 shows a block diagram of a conventional receiving device. In Figure 2, ■ is the antenna, 2 is the inductor, and 3 is the antenna.
is a trimmer capacitor, 4 is a varicap, 5 is an RF amplifier, 6 is an inductor, 7 is a trimmer capacitor, 8 is a varicap, 9 is a PLL synthesizer for local oscillation, 10
11 is a mixer, and 12 is an IF amplifier.

The tracking adjustment operation of the receiver configured as described above will be described below.

The oscillation output signal of the local oscillator consisting of the coil 6, trimmer capacitor 7, varicap 8, and PLL synthesizer 9 is supplied to the mixer 11, and the control voltage for the varicap 8 is also common to the varicap 4 in the high frequency amplification stage. is applied to Here, the tracking adjustment for the tuning section consisting of the inductor 2, the trimmer capacitor 3, and the varicap 4 is performed by adjusting the inductor 2 or the trimmer capacitor 3 to obtain the maximum sensitivity.

Problems to be Solved by the Invention However, in the above configuration, since the inductor or the trimmer capacitor is a mechanical adjustment component, there is a problem in that it cannot be automatically adjusted.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a receiving device that eliminates mechanical adjustment using an inductor or a trimmer cabaret, and can perform tracking adjustment using semiconductor technology.

Means for Solving the Problems In order to solve the above problems, the receiving device of the present invention has two varicaps installed in the middle stage tuner of the high frequency field, and the control voltage line in one of the varicaps is connected to the local oscillator. The control voltage line in the varicap is shared with the control voltage line in the other varicap, and the control voltage line in the other varicap is connected to the D/A converter and the memory.

According to the above-described configuration, the main tuning control of the middle-stage tuner in the high frequency field is performed by the control output signal of the PLL synthesizer for local oscillation, and the auxiliary tracking adjustment control is performed by the memory that stores data for obtaining the maximum sensitivity in advance. This is done using a signal obtained by converting the output signal of 1 to an analog control voltage by a D/A converter.

Embodiment Hereinafter, a receiving apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of a receiving device in an embodiment of the present invention. In FIG. 1, 13 is an antenna, 14 is an inductor, 15 and 16 are varicaps,
17 is an RF amplifier, 18 is an inductor, 19 is a varicap, 20 is a PLL synthesizer for local oscillation, 21 is a mixer, 22 is an IF amplifier, 23 is a memory, and 24 is a D
/A converter, 25 is a channel selector, and 26 to 28 are high frequency blocking resistors.

The operation of the receiving device configured as described above will be described below.

In FIG. 1, the main tuning control is that the control output voltage of the PLL synthesizer 2° to the varicap 19 for local oscillation is controlled by the Paris camp 16 in the tuner in the middle stage of the high frequency field.
This is done by applying . However, this alone cannot completely eliminate tracking errors over the entire reception band. Therefore, for the varicap 15, the output signal of the memory 23, which has previously stored data that minimizes the tracking error, is sent to the varicap 15.
The converted analog control voltage is applied via the A converter 24. The output signal of the channel selector 25 is supplied to a programmable counter (not shown) in the PLL synthesizer 20 for local oscillation to control the reception frequency, and is also used to specify the address of the memory 23, thereby corresponding to the reception term wave number. Control is performed to output data from the memory 23 that minimizes the tracking error. In this way, IF output is obtained with the highest sensitivity over the entire receiving frequency band.

In the embodiment, one set of the high-frequency field middle stage tuner (consisting of the inductor 14, varicaps 15 and 16), the memory 23, and the D/A converter 24 is shown, but the combination may be changed depending on the design. The number of sets to be used is arbitrary. In that case, the control output voltage of the PLL synthesizer 20 is commonly supplied to those corresponding to the function of the varicap 16, and the control output voltage of the PLL synthesizer 20 is commonly supplied to those corresponding to the function of the memory 23. For designation, the output signal of the single station selection device 25 is commonly supplied.

Effects of the Invention As described above, the present invention provides variable caps 15 and 16,
By providing a memory 23, a D/A converter 24, and a channel selector 25, it is possible to adjust the tracking pitch purely electronically. As a result, the best state of highly accurate tracking adjustment can be stably ensured over the entire reception frequency band for a long time, and a high-performance receiving device can be constructed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a receiving device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional receiving device. 14, 18...Inductor, 15.16.19
... Varicap, 20 ... PLL synthesizer, 23 ... Memory, 24 ...
・D/A converter, 25...Tuition selector ・17・
...RF amplifier, 21...Mixer. Name of agent: Patent attorney Toshio Nakao
N

Claims (1)

[Claims] A local oscillator is provided for the first group of voltage variable capacitance elements in at least one or more high frequency amplifier stage tuner in which first and second voltage variable capacitance elements each having arbitrary capacitance change characteristics are installed. A control voltage common to the control voltage applied to the voltage variable capacitance elements is applied to the second voltage variable capacitance element group, and control voltages that minimize the tracking error are independently applied to the second voltage variable capacitance element group. A receiving device characterized by: