A highly linear broadband common base mixer based on combination of active and resistive concepts

In this paper we present a new circuit design for broadband direct conversion mixer. The basic circuit structure is that of a common-base variable feedback amplifier. A good tradeoff between conversion gain, linearity, and consumption is obtained by combination of active and resistive techniques. Two prototypes have been made for different design trade-off. The maximum performances of the first are; a voltage conversion gain of +7.5 dB, an OIP3 of +23 dBm and an OIP2 of +51 dBm with a power consumption of 72 mW from 3.6 V supply. The second has a conversion gain less than +3.5 dB, a maximum OIP3 of +13 dBm and an OIP2 of +58 dBm with a power consumption of 40 mW from 3.6 V supply. The cut-off frequency for both prototypes is located above 2.6 GHz.