A CMOS Broadband Low-Noise Mixer With Noise Cancellation

This paper presents a broadband low-noise mixer in CMOS 0.13-mu m technology that operates between 1-5.5 GHz. The mixer has a Gilbert cell configuration that employs broadband low-noise transconductors designed using the noise-cancelling technique used in low-noise amplifer designs. This method allows broadband input matching and without the use of inductors that are frequently required in low-noise mixer designs. The current-bleeding technique is also used so that a high conversion gain can be achieved. Measured results show excellent noise and gain performance across the frequency span with an average double-sideband noise figure of 3.9 dB and a conversion gain of 17.5 dB. It has a third-order intermodulation intercept point of +0.84 dBm at 5 GHz and it is also very compact with the size of the mixer core only being 0.315 mm(2).