Abstract: Aiming at the passband division and suppression redundancy of the switching filter in broadband receiving front-end, a design method which can accurately give the passband division and out-of-band suppression index of the switching filter is proposed. First of all, by analyzing the selection of the first IF frequency need to consider the front switching filter,the first mixer, mirror frequency rejection filter, etc., the first IF frequency and the first local oscillator frequency are given. Then, through the accurate measurement of mixer spur and analysis, the division and out-of-band rejection index of switching filter frequency are obtained. The test of the switch filter chip shows that the first pass band can suppress 40 dBc at 38 GHz, which reaches the design target. Ka-band broadband receiver front-end test results show that gain ≥56 dB, in-band spur ≤−55 dBc, out-of-band spur ≤−45 dBc, gain consistency ≤2.8 dB and noise coefficient ≤8 dB in the entire RF input range of 33 GHz~40 GHz. The test results of switching filter and Ka broadband receiving front-end show the effectiveness of this design method, which can be widely used in various broadband and UWB(Ultra-wide Band) receiving front-end devices.