The invention provides an adjustable
negative resistance structure-based multimode multi-channel mixer, which comprises a
radio frequency input circuit, an adjustable
negative resistance circuit, a
digital control capacitor array circuit and a double-balanced differential structure circuit, wherein two input ports of the
radio frequency input circuit are connected with
radio frequency signals RF+ and RF-, and an output port of the radio frequency input circuit is directly connected with ports RFout+ and RFout-; the
negative resistance size of the adjustable negative resistance circuit is controlled by two levels Vctrll and Vctrl, and an output end of the adjustable negative resistance circuit is connected with the RFout+ and the RFout-; an input port of the
digital control capacitor array circuit is controlled by a
digital signal, and two output ports of the
digital control capacitor array circuit are connected with the RFout+ and the RFout-; and radio frequency current signals are input into the double-balanced differential structure circuit through the RFout+ and the RFout-, and are mixed with local oscillation signals LO+ and LO- to output intermediate-frequency signals IF+ and IF- to be then input into a rear-end module. By the adjustable negative resistance circuit, the equivalent parallel resistance of a capacitor array is eliminated, a
noise coefficient is reduced, the
gain of an
active mixer is improved, the working frequency of the mixer can be controlled by a digital end, and the requirements of a
broadband multi-channel
system are met.