JPS6328117A - Receiver - Google Patents

Abstract

PURPOSE:To make a tracking adjustment without using a coil nor a trimmer capacitor having a mechanical movable part by providing an offset memory for storing tracking adjustment data, a digital adder, and a D/A converter. CONSTITUTION:The channel selection digital signal of a channel selector 8 adjusts the oscillation frequency of a digital control local oscillator 7 and is also supplied to the offset memory 9 and digital adder 10. Here, the offset memory 9 is stored with the tracking adjustment data previously. Then the tracking adjustment data and channel selection digital signal are processed through the addition or subtraction of a digital adder 10 and the result is converted by a D/A converter 11 into an analog voltage, which is supplied to an RF amplifier 5. A variable tuning circuit which uses the voltage varactor diode is installed in the RF amplifier 5 and set to a necessary tuning frequency with the supplied analog voltage and then operates so as to the maximum sensitivity.

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 using semiconductor technology.

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

FIG. 3 shows a block diagram of a conventional receiving device. In FIG. 3, 1 is an RF amplifier, 2 is a mixer, 3 is a digitally controlled local oscillator, and 4 is a channel selector.

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

First, the oscillation output signal of the digitally controlled local oscillator 3 is fed to the mixer 2, while the analog control voltage is fed as a tuning control signal to the RF amplifier 1. Here, the tracking adjustment in the RF amplifier 1 is performed by adjusting the coil or trimmer capacitor (both not shown) of the tuning circuit inside the RF amplifier 1 to obtain the maximum sensitivity.

Problems to be Solved by the Invention However, in the above configuration, since the coil or trimmer capacitor is a mechanical adjustment component, there is a problem in that automatic adjustment cannot be performed.

In view of the above problems, the present invention provides a receiving device that eliminates mechanical adjustment using a coil or a trimmer capacitor 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 includes an offset memory for storing an adjustment signal, an adder for adding and subtracting the memory output and a digital control signal of a local oscillator, and a D/O. This device has a configuration and function in which an A converter is provided and tracking adjustment is performed using the analog output voltage of the A converter.

According to the above-described configuration, the present invention adds the digital control l signal for the digitally controlled local oscillator and the offset information signal of the offset memory whose address signal is the digital control signal using a digital adder, and outputs the addition output to D. It is converted into an analog voltage by a /A converter and used as a tuning control voltage for a voltage control tuner installed in an RF amplifier, and RF tuning control is performed in correspondence with the oscillation frequency of the digitally controlled local oscillator. This allows optimal tracking adjustment.

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 apparatus in a first embodiment of the present invention. In Figure 1, 5 is RF
amplifier, 6 is a mixer, 7 is a digitally controlled local oscillator,
8 is a channel selector, 9 is an offset memory, 10 is a digital adder, and 11 is a D/A converter.

The operation of the receiving device configured as above will be explained. In FIG. 1, the tuning digital signal of the tuning device 8 controls the oscillation frequency of the digitally controlled local oscillator 7, and the offset memory 9 and the digital adder lO.
Also supplied. Here, tracking adjustment data is manually stored in the offset memory 9 in advance.

Then, the tracking adjustment data and the channel selection digital signal are added and subtracted by a digital adder 10, and the D/A
Converter 11 converts it into an analog voltage and RF amplifier 5
supply to. The RF amplifier 5 is equipped with a variable tuning circuit (not shown) using a voltage variable capacitance diode, etc., and can be set to a desired tuning frequency and operated to obtain maximum sensitivity using the supplied analog voltage. .

As described above, according to this embodiment, by providing an offset memory for storing tracking adjustment data, a digital adder, and a D/A converter, tracking can be achieved without using a coil having a mechanically movable part or a trimmer capacitor. Adjustment is possible. By storing individual tracking adjustment offset data for each channel selection digital code, complete tracking adjustment can be performed over all reception channels, and tracking errors can be completely eliminated.

A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram of a receiving device showing a second embodiment of the present invention.

In the figure, 12 is an RF amplifier, 13 is a mixer, and 14 is an RF amplifier.
is a digitally controlled local oscillator, 15 is a channel selector, 16 is an offset memory, 17 is a digital adder, and 18 is a D
/A converter, which has the same structure as that shown in FIG. The difference from the configuration shown in FIG. 1 is that an address memory 19 is provided between the channel selector 15 and the offset memory 16.

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

A part of the digital control signal of the channel selector 15 is supplied as an address signal to the offset memory 16 through the address memory 19, and the relationship between the digital control signal and the address signal is arbitrarily set in the address memory 19.

As described above, by setting the address memory 19 between the channel selector 15 and the offset memory 16, for example, by arbitrarily grouping the selected channels and making the address of the offset memory 16 common, it is possible to solve problems in practical use. The memory capacity of the offset memory 16 can be saved within a range where tracking errors occur to a certain degree.

Effects of the Invention As described above, the present invention has an offset memory for storing tracking adjustment data, a digital adder, and a D/
By providing the A converter, tracking adjustment can be performed without using a coil or trimmer capacitor having a mechanically movable part. Additionally, tracking can be adjusted completely across all receiving channels, eliminating tracking errors. Furthermore, the tracking adjustment function can be completely integrated into semiconductors, making it possible to automate the adjustment and make the receiving stage ultra-small.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a receiving device according to a first embodiment of the present invention, FIG. 2 is a block diagram of a receiving device according to a second embodiment of the present invention, and FIG. 3 is a conventional receiving bag! This is a professional drawing. 5.12...RF amplifier, 6,13...
・Mixer, 7.14... Digitally controlled local oscillator, 8, 15... Tuning selector, 9, 16...
...offset memory, 10°17...digital adder, 11.18...D/A converter, 19...address memory. Name of agent: Patent attorney Toshio Nakao 1 person, 1 person - 8 people

Claims (2)

[Claims] (1) The digital control signal for the digitally controlled local oscillator is shared with the address signal of the offset memory, the memory output signal of the offset memory and the digital control signal are added and subtracted in an adder, and the output signal of the adder is converted into a D/A signal. The analog voltage is supplied to a converter and converted into an analog voltage, and the analog voltage is supplied as a tuning control signal to an RF amplifier, and the output of the RF amplifier is mixed with the oscillation output of the digitally controlled local oscillator by a mixer to generate an IF output. A receiving device characterized by: (2) The reception according to claim 1, characterized in that an address memory is installed between the digital control signal for the digitally controlled local oscillator and the address signal of the offset memory in order to arbitrarily set the relationship between the digital control signal and the address signal of the offset memory. Device.