On the implementation of a very low-spurious Si-bipolar frequency multiplier

Analytical expressions are obtained for the output components of a Gilbert cell mixer excited by two large signals of equal normalized amplitude and frequency. Assuming identical transistors, no odd-order products are produced by the Gilbert cell mixer. This simplifies the design of the Si-bipolar frequency multiplier proposed by Yamaguchi et al., IEICE Transactions Electronics, 1999, pp. 1092-1097, as no single-end/differential converter is required to convert the sinusoidal input signal into a rectangular waveform. This results in a smaller chip area and less power consumed by the proposed frequency-multiplier built around the Gilbert cell mixer. The effect of the difference in the transistor area and/or bias offset is also considered. SPICE simulation results are included.