2.4 GHz discrete‐time receiver without subsampling mixer

Abstract

A subsampling filter is proposed for a discrete-time receiver (DTR). This filter achieves signal discretisation, filtering and downconversion simultaneously. With the proposed subsampling filtering technique, the subsampling mixer in a conventional DTR is eliminated, which can reduce power, cost and noise. The first 2.4 GHz DTR prototype for Zigbee application is fabricated in a 0.18 μm CMOS process. It achieves 23 dB conversion gain, 17.6 dB noise figure and −15 dBm IIP3. Operated from a single 1 V supply, the low-noise amplifier and following filter stages consume only 3.8 mW and the total receiver power consumption is 25.6 mW.

A 2.4 GHz 2.2 mW current reusing passive mixer with gm-boosted common-gate TIA in 180 nm CMOS

“…The mixer core and the total power consumption of the mixer are 2.2 mW and 3.2 mW respectively under the supply voltage of 1.8 V. The embedded LO buffer provides LO signal with fixed amplitude. [6], active mixers [7,8], sub-sampling mixer [9] and discrete sampling receiver [10]. The working frequencies of the listed mixers are all within the L and S band.…”

“…With the reduction in IC feature size, the conducting resistance and the parasitic capacitance of MOS switches decreases significantly, which encourages the technique development and mass usage of passive mixers [1,2,3,4,5,6]. Compared with active mixers such as Gilbert mixers [7,8], the sub-sampling mixer [9] and the discrete sampling receiver [10], a passive mixer achieves higher conversion gain and better linearity. Thus it has become a promising choice to build an RF receiver.…”

Discrete-time Receivers, from N-Path to Charge Sharing Band-pass Filters: a Comparison

“…N-path based receivers usually benefit from the direct conversion (DC) IF architecture [11,[14][15][16], perhaps with a few exceptions in low intermediate-frequency (IF) like [12,13,35]. On the other hand, discrete-time receivers (DT-RX) are used in super-heterodyne or high IF (HIF) architectures [20-22, 25-28, 32, 36, 37], and in direct conversion [18,19,31,38,39]. While DC-IF architectures lead to the absence of image issues, high-IF offers other interesting features like improved resilience to second-order intermodulation, dc offset, and flicker-noise.…”