A fully analog side-band cancellation technique in radio-frequency transmitters

作者：Nikoofard Ali^*; Kananian Siavash; Hadizadeh Ehsan; Fotowat Ahrnady Ali

来源：Microelectronics Journal, 2016, 53: 116-126.

DOI：10.1016/j.mejo.2016.04.014

• I/Q imbalances
• I/Q mismatch cancellation
• Error vector magnitude (EVM)
• Side-band rejection ratio (SRR)
• Transmitter chain (TX)
• Direct-conversion TX

In this paper, a new fully analog technique is proposed by means of which the adverse effects of frequency dependent gain/phase errors in quadrature transmitters are suppressed. Two separate phase and gain mismatch cancellation loops are implemented which search for the minimum side-band component. A new sign detection method is also introduced which makes sure the direction of the loop is correct. Analytical models and mathematical derivations have been presented which corroborates the circuit implementation. A proof of concept prototype using off-the-shelf components have also been measured which suggests 38-dB side-band rejection (SBR). Furthermore, the measured TX EVM and BER are improved by an order of magnitude for a QPSK-modulated input signal.

• 出版日期2016-7