KR20000002558A - Reception device of wireless phone - Google Patents

Abstract

PURPOSE: A reception device of a wireless phone is provided to increase productivity with simplification of parts as well as to make reception sensitivity of a wireless phone better. CONSTITUTION: The reception device of a wireless phone comprises: a first mixing part(140) changing a first intermediate frequency by mixing high frequency from an antenna and the departure frequency of the first section departure part; an intermediate frequency amplifying part(150) amplifying the first intermediate frequency of the first mixing part; and the second mixing part changing the second intermediate frequency by mixing the first intermediate frequency and the departure frequency of the second section departure part.

Description

Receiver of cordless phone

The present invention relates to a receiver of a wireless telephone, and more particularly, to a receiver of a wireless telephone having a structure in which the intermediate frequency of the first mixing section amplified by the intermediate frequency amplifier can be directly demodulated through a demodulator.

In general, a wireless telephone is roughly divided into a receiving apparatus for demodulating and outputting a high frequency signal inputted from an antenna into an audible sound signal, and a transmitting apparatus for modulating a user's voice signal and propagating it in the air. The explanation is as follows.

1 is a block diagram showing a receiver of a typical wireless telephone.

As shown in FIG. 1, a receiver of a wireless telephone includes an input filter unit 11 for removing a noise signal included in a high frequency signal induced through an antenna ANT, and filtering through the input filter unit 11. A high frequency amplifying unit 12 for maximum amplifying the high frequency signal, a high frequency signal of the high frequency amplifying unit 12 and an oscillation frequency of the first local oscillating unit 13 to convert the first high frequency signal into a first intermediate frequency IF1; A first mixing section 14, an intermediate frequency amplifying section 15 for amplifying the first intermediate frequency IF1 of the first mixing section 14, and the first amplified by the intermediate frequency amplifying section 15. A second mixing section 17 for mixing the oscillation frequencies of the first intermediate frequency IF1 and the second local oscillating section 16 to a second intermediate frequency IF2, and a second of the second mixing section 17; A demodulator 18 which demodulates the intermediate frequency IF2 and outputs the audible sound signal; the first local oscillator 13; 2 comprises a local oscillation unit and the phase locked loop 19 for each stabilizing an oscillation frequency of 16, a microcomputer 20 for controlling the phase-locked loop (19).

The operation of the receiver of the wireless telephone having the above configuration will be described below.

First, when the high frequency signal is induced from the antenna ANT, the input filter unit 11 removes the unnecessary noise signal included in the high frequency signal input from the antenna ANT, and then applies the high frequency signal to the high frequency amplifier 12 at the rear stage. Allow amplification.

In the first mixing unit 14, the oscillation frequency of the first local oscillator 13 under the control of the microcomputer 20 and the phase synchronization loop 19 and the high frequency signal amplified by the high frequency amplification unit 12 are the maximum. The mixture is converted to the first intermediate frequency IF1. The first intermediate frequency IF1 is amplified by the intermediate frequency amplifying unit 15 and applied to the second mixing unit 17 at the rear stage.

Thereafter, the second mixer 17 amplifies the oscillation frequency of the second local oscillator 16 under the control of the microcomputer 20 and the phase-locked loop 19 and the intermediate frequency amplifier 15. The first intermediate frequency IF1 is mixed and converted back to the second intermediate frequency IF2 to be output as a final audible signal to the user through the demodulation process of the demodulator 18.

However, since the receiver of the wireless telephone according to the related art which achieves the above-described configuration and operation, the mixing unit for mixing the high frequency signal induced from the antenna ANT with the oscillation frequency and converting it into an intermediate frequency is composed of two stages. The product requires a lot of parts and has a large volume, which greatly reduces productivity.

Accordingly, the present invention has been made to solve the above-mentioned problems, and the object of the present invention is that the intermediate frequency of the first mixing section amplified by the intermediate frequency amplification section can be directly demodulated through the demodulation section. It is to provide a receiver of a radiotelephone which leads to an improvement in productivity due to the simplification of components by omitting the mixing portion and the second local oscillation portion.

1 is a block diagram showing a receiver of a typical wireless telephone.

2 is a block diagram showing a receiving apparatus of the wireless telephone according to the present invention.

* Description of the symbols for the main parts of the drawings *

ANT: antenna 110: input filter unit

120: high frequency amplifier 130: first local oscillator

140: first mixing unit 150: intermediate frequency amplifier

160: demodulation unit 170: phase synchronization loop

180: micom

The present invention for achieving the above object, the first mixing unit for mixing the high frequency signal and the oscillation frequency of the first local oscillation unit derived from the antenna to convert to the first intermediate frequency, and the first intermediate frequency of the first mixing unit A second mixing unit for mixing the oscillation frequencies of the intermediate frequency amplifying unit, amplifying the first intermediate frequency and the second local oscillating unit amplified by the intermediate frequency amplifying unit, and converting the oscillation frequencies into a second intermediate frequency; A receiver for a radiotelephone comprising a demodulator for demodulating a second intermediate frequency and outputting it as an audible signal, wherein the first mixing unit omits the second mixing unit and the second local oscillating unit that produce the second intermediate frequency. The demodulator receives the first intermediate frequency amplified by the intermediate frequency amplification unit and causes the demodulator to generate an audible signal. It is a basic feature of the technical configuration to enable the output to.

Hereinafter, a preferred embodiment of the wireless telephone according to the present invention will be described with reference to FIG.

2 is a block diagram showing a receiving apparatus of a wireless telephone according to the present invention.

As shown in FIG. 2, the receiver of the wireless telephone includes an input filter unit 110 for removing a noise signal included in a high frequency signal induced through an antenna ANT, and filtering through the input filter unit 110. A high frequency amplifying unit 120 for maximum amplifying the high frequency signal, a high frequency signal of the high frequency amplifying unit 120 and an oscillation frequency of the first local oscillating unit 130 are mixed and converted into a first intermediate frequency IF1. The first mixing unit 140, the intermediate frequency amplifier 150 for amplifying the first intermediate frequency IF1 of the first mixing unit 140, and the first amplified by the intermediate frequency amplifier 150 A demodulator 160 for demodulating one intermediate frequency IF1 as an audible signal, a phase synchronization loop 170 for stabilizing oscillation frequencies of the first local oscillator 130 and the second local oscillator, respectively; The microcomputer 180 controls the phase synchronization loop 170.

Referring to the operation of the receiver of the radiotelephone according to the present invention having the above configuration is as follows.

First, when a high frequency signal is induced from the antenna ANT, the input filter unit 110 removes an unnecessary noise signal included in the high frequency signal input from the antenna ANT, and then applies it to the high frequency amplifying unit 120 at a later stage to maximize it. Allow amplification.

In the first mixing unit 140, the oscillation frequency of the first local oscillator 130 under the control of the microcomputer 180 and the phase synchronization loop 170 and the high frequency signal amplified by the high frequency amplifying unit 120 are the maximum. The mixture is converted to the first intermediate frequency IF1, and the first intermediate frequency IF1 is again amplified by the intermediate frequency amplifier 150 and applied to the demodulator 160 at a later stage.

Thereafter, the first intermediate frequency IF1 amplified by the intermediate frequency amplifier 150 is output to the user as a final audible signal through a demodulation process of the demodulator 160.

Here, since the first intermediate frequency IF1 produced in the first mixing unit 140 is amplified by the intermediate frequency amplifier 150 and then directly applied to the demodulator 160, the demodulation sensitivity is clear and the audible sound is clear. There is an action that can output a signal.

As described above, according to the receiver of the wireless telephone according to the present invention, the second mixing unit and the second local oscillating unit are configured such that the intermediate frequency of the first mixing unit amplified by the intermediate frequency amplifying unit can be directly demodulated through the demodulation unit. By omitting, not only the reception sensitivity of the voice signal is improved, but also the excellent effect of expecting an improvement in productivity due to the simplification of components is expected.

Claims (1)

A first mixing unit for mixing the high frequency signal induced from the antenna and the oscillation frequency of the first local oscillation unit and converting the oscillation frequency into a first intermediate frequency, an intermediate frequency amplifier for amplifying the first intermediate frequency of the first mixing unit, and the intermediate unit A second mixing unit for mixing the oscillation frequencies of the first intermediate frequency and the second local oscillation unit amplified by the frequency amplifying unit and converting the oscillation frequencies into a second intermediate frequency; and demodulating a second intermediate frequency of the second mixing unit as an audible signal. In the receiving device of a wireless telephone comprising a demodulator for outputting, By omitting the second mixing unit and the second local oscillating unit that produce the second intermediate frequency, the demodulator receives the first intermediate frequency output from the first mixing unit as amplified by the intermediate frequency amplifying unit. A wireless telephone receiver, characterized in that for outputting an audible signal.