An FDD Wireless Diversity Receiver With Transmitter Leakage Cancellation in Transmit and Receive Bands

Abstract

Antenna-coupling group delay limits the cancellation bandwidth of conventional self-interference cancellers (SICs), making it difficult to ensure isolation in both transmit (TX) and receive (RX) bands. Isolation over both bands is achieved in the dual-path receiver architecture proposed in this paper. The main path consists of a highly linear current-mode RX with a passive RF SIC. The auxiliary path implements a notch in the TX band followed by an adaptive digital equalizer whose output is used to suppress the TX noise leakage in the RX band. The main and auxiliary receiver prototypes, implemented in 28-nm CMOS technology, operate between 1 and 2 GHz, occupy an area of 0.51 and 0.12 mm 2 , and have a power dissipation of 32-40 and 26-64 mW, respectively. The stand-alone RX has a noise figure (NF) of 4-5 dB and an out-of-band IIP3 of 18 dBm. Turning on the passive canceller results in an effective IIP3 of 25-29 dBm and a degradation of the NF of less than 0.8 dB. Thanks to its high dynamic range, the auxiliary path suppresses the TX noise by >29 dB while degrading the RX NF by only 1 dB at 23-dBm TX output power.

Analysis and mitigation of noise in simultaneous transmission and reception in MRI

“…Transmit noise can be considered as the noise input to the transmit system (generated by spectrometer) multiplied by the transmit gain and the additional contributions of other noise generating elements (amplifiers and the cancellation circuit) as summarized in Equation (). With proposed cancellation hardware, it is shown that it is possible to isolate the transmit noise in addition to the leak signal for a given transmit gain, consistent with the works by Montanari et al, 25 Zhou et al, 26 and Emara et al 25 …”

Low-Frequency Noise in CMOS Switched-gm Mixers: A Quasi-Analytical Model

“…The transfer function decreases as the LO frequency goes up, corresponding to decreased STLO. Although the transconductance flicker noise transferred to output is decreased with decreased STLO, the accompanied conversion gain also degrades as disclosed in (1) and (3). Moreover, as in the previous analysis, the transconductance flicker noise is also modulated by the random offset voltage Vos3 applied to the gate of switches.…”

“…Specifically, for tentative specifications of thermal noise figure, NF=10 dB, and conversion gain CG=13 dB, the parameter requirements for gm0=11 mS and RL=800 Ω is computed by (1) and (18) with typical S as in Table 1. And it is also verified that t1 =27 ps.…”

“…Direct conversion architectures, with the merits of high integration and low costs, have drawn great attention in the last decades from both industry and academia. However, the direct conversion receiver (DCR) for systems on chip (SOC) target [1] still has been deeply obsessed with a few drawbacks yet to be well addressed, such as flicker noise, dc offset, even-order distortion, and local oscillator (LO) leakage. Undoubtedly, flicker noise among them is a critical issue in the DCR design as it almost degrades the signal-to-noise ratio (SNR) and total noise figure (NF), which eventually results in the deterioration of the receiver's sensitivity [2].…”

Investigation and Suppression of RF Leakage Power in Front End Wireless Devices

“…H. Khatri et al,(2010) and A. Cicalini et al,(2006) proposed TX leakage filtering active cancellation techniques [9][10][11]. Lederer and Huemer (2011), Frotzscher and Fettweis (2008), and Kahrizi et al,(2008) discussed interference cancellation algorithms using adaptive based LMS and measured error to suppress noise through stopband of the frequency flat duplex [12][13].…”