Method for high-frequency amplifier using power gain-boosting technique

摘要

The present invention provides a power gain-boosting technique for an amplifier in order to compensate for the decrease of Gmag in a transistor at high frequencies. A power gain-boosting technique of the present invention comprises the steps of: finding the Maximum Unilateral Gain or Mason's Invariant U of a transistor; designing a linear, lossless, reciprocal network embedding the transistor so that the final equivalent S-, Y-, or Z-parameters satisfy the condition:;S⁢21S12=Y2⁢⁢1Y1⁢⁢2=Z2⁢⁢1Z1⁢⁢2=-[(2⁢U-1)+2⁢U⁡(U-1)];
embedding the transistor into the linear, lossless, reciprocal network; and constructing simultaneous conjugate matching.

主权项

1. A method of designing a high frequency amplifier, comprising the steps of:
finding intrinsic Z-parameters of a transistor; finding the Maximum Unilateral Gain or Mason's Invariant U of the transistor; calculating Gmag(max) which satisfies the condition: (2U−1)+2√{square root over (U(U−1))}=−A; decreasing the value of |A| from the previous step until the stability factor k is slightly higher than 1, according to the equation:U=S21S12-122⁢k⁢S21S12-2⁢Re⁡(S21S22); designing a linear, lossless, reciprocal network embedding the transistor such thatS21S12=Y21Y12=Z21Z12equals the value of A from the previous step;
embedding the transistor into the linear, lossless, reciprocal network; and constructing simultaneous conjugate matching, wherein S12 and S21 represent S-parameters of the transistor and S12eq and S21eq represent S-parameters of the linear, lossless, reciprocal network embedding the transistor, Y12eq and Y21eq represent Y-parameters of the linear, lossless, reciprocal network embedding the transistor, and Z12eq and Z21eq represent Z-parameters of the linear, lossless, reciprocal network embedding the transistor.