Receiver

Abstract

The object of the present invention is to provide a receiver which can reduce low-frequency noise generated when it is integrally formed on a semiconductor substrate using a CMOS process or a MOS process. High-frequency amplifying circuit (11), frequency mixing circuit (12), local oscillator (13), intermediate frequency filter (14, 16), intermediate frequency amplifier (15), limiting circuit (17), The FM detection circuit (18) and the stereo demodulation circuit (19) are formed as one-chip components (10). The single-chip element (10) is formed on a semiconductor substrate using a CMOS process or a MOS process, and a p-channel FET is used to form a mixing circuit (12), an intermediate frequency filter (14, 16), an intermediate frequency amplifier (15) and a local The amplifying element contained in the oscillator (13).

Description

Technical field [0001] The present invention relates to a receiver that performs frequency conversion on a received signal. Background technique [0002] Generally, a receiver that adopts the superheterodyne method amplifies the modulated signal received by the antenna at a high frequency, then uses a mixer circuit to perform frequency conversion, and then performs demodulation after the conversion into an intermediate frequency signal with a predetermined frequency. [0003] Particularly recently, research on the technology of integrally forming an analog circuit containing high-frequency components on a semiconductor substrate using a CMOS process or a MOS process has been conducted, and some devices have been put into practical use. By using the CMOS process or the MOS process to form various circuits on a single chip, the entire device can be miniaturized or reduced in cost. Therefore, it is possible to consider expanding the range of devices formed on a single chip in the fu...

AI Technical Summary

Problems solved by technology

[0004] If each element of a conventional superheterodyne receiver is formed on a single chip using a CMOS process or a MOS process, there is a problem of low-frequency noise called 1 / f noise

Generally, MOS-type FETs are characterized by large 1 / f noise compared to bipolar transistors, and if each element constituting the receiver is formed on a single chip using a CMOS process or a MOS process, it is used as an amplification element included in it. FET becomes a noise source of 1 / f

Moreover, when using a frequency mixing circuit to convert a high-frequency modulation signal into an intermediate-frequency signal with a lower frequency, since the 1 / f noise component occupies a high proportion of the intermediate-frequency signal, the S / N (signal-to-noise Ratio) decreases and the reception quality deteriorates

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