| 摘要 |
PROBLEM TO BE SOLVED: To obtain a gilbert cell mixer of a wide linear range without an additional diode pre-distortion circuit by using a multi-hyperbolic tangent tablet or a multi-hyperbolic tangent triplet. SOLUTION: In order to extend the linearity of the top quad cores of normally used transistors Q1 to Q4 as the local oscillator port of an active mixer, the multi-hyperbolic tangent tablet is assembled to a gilbert cell topology. The multi-hyperbolic tangent tablet includes the four transistors Q1 to Q4 and the transistors Q2 and Q4 are provided with emitters area (e). The transistors Q1 and Q3 are provided with emitter areas Ae. In addition, Ae is A-times as large as the emitter area (e). By optimizing the areas Ae of the transistors Q1 and Q3 with respect to the transistors Q2 and Q4 , highestly flat DC mutual conductance characteristic is obtained. |
