CN1206244A

CN1206244A - Medium frequency output-less bridge balance mixer with monochip IC and microwave FET

Info

Publication number: CN1206244A
Application number: CN 98115816
Authority: CN
Inventors: 吴咏诗; 张进心; 王安国
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 1998-07-10
Filing date: 1998-07-10
Publication date: 1999-01-27
Anticipated expiration: 2018-07-10
Also published as: CN1110123C

Abstract

The balance mixer without medium frequency output bridge has very small circuit area suitable for monochip integration. It has two radio-frequency input bridges or phase shifters at the radio frequency input and the radio signal voltage and the local oscillation voltage applied to FET are equal in amplitude but opposite in phase, so that there is no need of bridge at the medium- frequency output end in obtaining excellent performance. Owing to the high frequency of radio frequency terminal, the bridge or phase shifter has small size for monochip integration.

Description

Zero intermediate frequency output electric bridge single face monolithic integrated circuit microwave field effect transnistor balanced mixer

The present invention relates to a kind of single face monolithic integrated circuit microwave field effect transnistor balanced mixer.

Microwave mixer is the vitals in the microwave systems such as communication, radar, electronic instrument.The microwave field effect transnistor balanced mixer is owing to have higher conversion gain, and the rejection of local oscillator noise and image frequency component is subjected to paying attention to widely preferably.But in the metal-semiconductor field effect transistor balanced mixer of using, need electric bridge at rf inputs and realize that the level of radiofrequency signal and local oscillator input distributes and mutual isolation at present.Also need electric bridge at medium frequency output end and realize the addition of intermediate-freuqncy signal and the inhibition of local oscillator noise and image frequency component.These two electric bridges will occupy sizable area on chip, especially in low-converter, the frequency of intermediate frequency is lower, and the size of output electric bridge will be in a centimetre magnitude.Therefore, circuit is can't monolithic integrated.

The microwave field effect transnistor balanced mixer that the purpose of this invention is to provide a kind of zero intermediate frequency output electric bridge, because zero intermediate frequency output electric bridge, the area of circuit will greatly reduce, thereby just can realize that monolithic is integrated.

The present invention realizes as follows, as shown in Figure 1 be the field effect transistor gate balanced mixer.Radiofrequency signal (RF) is divided into the signal that the two-way amplitude equates through power splitter 1, adds to the input of two radio frequency input bridges respectively.Local oscillation signal (L0) is divided into the input that the equal signal of two-way amplitude adds to two radio frequency input bridges respectively through power splitter 2.Just two of power splitter 1 outputs are connected with the input of radio frequency input bridge 1 with radio frequency input bridge 2 respectively, and two outputs of power splitter 2 are connected with 2 input with radio frequency input bridge 1 respectively.Radio frequency input bridge 1 phase shift of joining with field-effect transistor T1 is that 0 ° output and the grid of T1 join, and phase shift is that 180 ° output passes through matched impedance ground connection.With the radio frequency input bridge 2 that field-effect transistor T2 joins, phase shift is that 180 ° output and the grid of T2 join, and phase shift is that 0 ° output passes through matched impedance ground connection.The drain electrode of two field effect transistor T1, T2 and the input of filter join, and obtain output signal, the source ground of two field effect transistor T1, T2 by the output of filter.

The two paths of signals amplitude that arrives T1, T2 grid like this equates that phase place is opposite, carries out non-linear frequency mixing by T1, T2, is exported by the drain electrode of T1, T2 respectively; Directly addition can curb local oscillator and image frequency signal then, and the output by intermediate-frequency filter obtains intermediate-freuqncy signal at last.

The field effect transistor drain electrode frequency mixer that provides in the accompanying drawing 2, the output of its phase shifter and the grid of field-effect transistor T1, T2 link, the drain electrode of the output of another phase shifter and field-effect transistor T1, T2 is joined and is joined with the input of filter, obtains intermediate-freuqncy signal by filter.Radiofrequency signal (RF) is divided into amplitude and equates behind phase shifter, the two paths of signals that phase place is opposite adds to the grid of field-effect transistor T1 and T2 respectively.Local oscillation signal (L0) is divided into amplitude through another phase shifter and equates that the two paths of signals that phase place is opposite adds to the drain electrode of field-effect transistor T1 and T2 respectively.The source ground of field-effect transistor T1 and T2.

By the non-linear frequency mixing of field-effect transistor T1 and T2, the direct addition of drain electrode output signal with two pipes can curb local oscillator and image frequency signal, obtains intermediate-freuqncy signal through intermediate-frequency filter.

The field-effect transistor balanced mixer of zero intermediate frequency output electric bridge is with two power splitters and electric bridge or only make radio-frequency input signals and local oscillation signal be divided into amplitude separately with two phase splitters to equate at rf inputs, two signals that phase place is opposite are added in respectively on two field-effect transistors.The direct addition of the output signal of two pipes need not intermediate frequency output electric bridge, can curb local oscillator and image frequency signal, obtains the intermediate frequency output signal of addition.Because do not need intermediate frequency output electric bridge, and radio frequency and local frequency are significantly higher, radio frequency input bridge size is less, circuit significantly reduces (can reduce to below 1/10) in shared size on the chip, thereby just can monolithic integrated.

Claims

A kind of zero intermediate frequency output electric bridge single face monolithic integrated micro field-effect transistor balanced mixer that constitutes by field-effect transistor etc., two outputs that it is characterized in that power splitter 1 and power splitter 2 intersect with the input of radio frequency input bridge 2 with radio frequency input bridge 1 respectively and are connected, radio frequency input bridge 1 and radio frequency input bridge 2 respectively have an output through matched impedance ground connection, radio frequency input bridge 1,2 separately another outputs are connected with the grid of T2 with field-effect transistor T1 respectively, field-effect transistor T1, input with filter after the drain electrode of T2 is joined joins, the output of filter obtains intermediate frequency output signal, field effect transistor T1, the source ground of T2; Perhaps the output of phase shifter 1 is connected with the grid of field-effect transistor T1, T2, after being connected with the output of phase shifter 2, the drain electrode of field-effect transistor T1, T2 is connected with filter input end, filter output output intermediate-freuqncy signal, the source ground of field-effect transistor T1, T2.