An Integrated Two-Mode Tunable Channelized Low-Noise Active Filter

Abstract

In this paper, a new structure for an integrated channelized active filter is proposed. This filter can be used as a channelized bandpass filter and again as a channelized band-stop filter. This is fulfilled by using one biasing voltage. In designing a three-channel bandpass filter, a recursive differential structure is used. Moreover, by subtracting bandpass filter output from an all-pass output, the proposed three-channel band-stop filter is achieved. A wideband amplifier plays the role of an all-pass filter. In addition, to decrease the noise of this filter, a noise-canceling circuit is adopted. By using this circuit, input impedance matching is obtained simultaneously. The center frequencies of the two-mode channelized filter are 2, 4 and 6[Formula: see text]GHz. In each of them, the center frequency is controlled via two biasing voltages. The maximum center frequency shift is 450[Formula: see text]MHz. For designing the proposed circuit, GaAs 0.15[Formula: see text][Formula: see text]m technology is applied. The occupied area is [Formula: see text][Formula: see text]mm2.