Unlock instant, AI-driven research and patent intelligence for your innovation.

Receiver circuit

A receiving circuit and circuit technology, applied in electrical components, reducing electrical interference, reducing interference caused by sinusoidal oscillation, etc., can solve problems such as reduced receiving sensitivity

Inactive Publication Date: 2007-09-12
SANYO ELECTRIC CO LTD
View PDF0 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] In this way, components of frequency IF2 caused by high harmonic components are mixed into S IF2 In the middle, there is a problem that noise such as a beat frequency (beat) is generated from the reproduced sound through the band-pass filter (BPF) 30, and the receiving sensitivity is lowered.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Receiver circuit
  • Receiver circuit

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0021] Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.

[0022]FIG. 1 is a block diagram showing a schematic circuit configuration of a double-conversion AM radio receiver as an embodiment of the present invention. The main part of the receiving circuit is formed in an integrated circuit (IC) 50 . The IC 50 includes a first local oscillation unit 52 , a first mixing circuit 54 , a BPF 56 , a second local oscillation unit 28 , a second mixing circuit 60 , a BPF 62 , an amplifier circuit 64 , and an AM detection circuit 66 .

[0023] The first local oscillation unit 52 includes a first oscillation circuit 70 and an n frequency division circuit 72, and the second local oscillation unit 58 includes a second oscillation circuit 74, a frequency division circuit 76, and a low-pass filter ( LPF)78 constituted.

[0024] The RF signal S from the antenna 80 is input to the IC5...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

In double-conversion receiver circuits, higher harmonics of a first local oscillating signal SLO1 and higher harmonics of a second local oscillating signal SLO2 enter a mixing circuit that converts a first intermediate frequency IF 1 into a second intermediate frequency IF 2 , resulting in problems in that frequency IF 2 signal components that are generated by the mixture of the two signals cause decreased sensitivity. As a countermeasure, an LPF 78 is provided between a second mixer circuit 60 and a divide-by-two frequency divider circuit 76 that supplies the signal SLO2 to the second mixer circuit 60 . The LPF 78 removes the higher harmonic components of the signal SLO2 that may be generated in the divide-by-two frequency divider circuit 76 . Even when higher harmonic components of the signal SLO1 that may be generated in a divide-by-n frequency divider circuit 72 enter the second mixer circuit 60 through the semiconductor substrate and the like, the higher harmonic components of the second local oscillating signal SLO2 are not mixed in, and the occurrence of signal components of the frequency IF 2 that result from higher harmonics being mixed in can thereby be prevented.

Description

technical field [0001] The present invention relates to a receiving circuit of a double conversion method for receiving a wireless transmission signal, and particularly relates to improvement of sensitivity. Background technique [0002] In AM radio receivers and the like, a double conversion method is known as a circuit configuration for improving frequency selectivity. FIG. 2 is a block diagram showing a circuit configuration of a conventional double-conversion AM radio receiver. The main part of the receiving circuit is formed in an integrated circuit (IC) 2 . The first mixing circuit 4 converts the first local oscillation signal S output from the first local oscillation unit 6 LO1 and the RF (Radio Frequency) signal S obtained from the antenna 8 RF Mix and convert the target received signal to the first intermediate frequency signal S of the specified intermediate frequency IF1 IF1 . The second mixing circuit 10 mixes the second local oscillation signal S output fro...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H04B1/10
CPCH04B1/28H04B15/06H04B1/10
Inventor 铃木顺
Owner SANYO ELECTRIC CO LTD