A CMOS Wideband RF Front-End With Mismatch Calibrated Harmonic Rejection Mixer for Terrestrial Digital TV Tuner Applications

A wideband RF receiver with extended statistical element selection based harmonic rejection calibration

“…A harmonic rejection mixer scheme, which was first proposed in [2] for a transmitter design, has been widely adopted in modern wideband RF receiver designs [3][4][5][6][7][8][9][10][11] to alleviate this problem. The basic idea is to construct an equivalent LO signal that is free of 3rd and 5th order harmonics, such that the 3rd and 5th order harmonic interferer would not be down-converted by the mixer, therefore being completely rejected.…”

“…In addition to relying on the intrinsic matching of CMOS process, calibration methods [7,8] have also been proposed to increase the HRR. These methods rely on a common technique in which gain mismatch cancels phase mismatch.…”

“…However, different phase and gain setting are needed to optimize HRR 3 and HRR 5 , respectively, resulting in the optimization of either HRR 3 or HRR 5 , not both. In [7,8] the authors calibrate the gain mismatch of the HR mixers and achieve a HRR 3 of approximately 70 dB. However, a degradation of HRR 5 after HRR 3 calibration is reported in [7].…”

“…In [7,8] the authors calibrate the gain mismatch of the HR mixers and achieve a HRR 3 of approximately 70 dB. However, a degradation of HRR 5 after HRR 3 calibration is reported in [7]. In [9], both gain and phase are tunable but the achieved HRR 3 is limited to 65 dB.…”

“…As compared to traditional post-fabrication mismatch calibration method, such as in [7,16], the ESES method can provide very fine tuning resolution without the need of implementing very small calibration units which can be challenging and costly in some applications. For example, implementing small current sources for current steering DAC calibration leads to large area overhead of calibration units [16].…”