Mallesh Rajashekharaiah

A new gain controllable on-chip active balun for 5 GHz direct conversion receiver

An on-chip active balun with gain and phase mismatch within 0.5 dB and 1 degree, respectively, integrated with a gain controllability feature, is presented. Applicable for direct conversion receiver circuits, the balun has been designed to operate in the 5-6 GHz range with a bandwidth of 400 MHz. With an output P1dB of -14.4 dBm, it is capable of being used as an independent amplifier in addition to acting as an active balun.

A 5.6-GHz CMOS doubly balanced sub-harmonic mixer for direct conversion -zero IF receiver

A new low power 5.6 GHz doubly balanced sub-harmonic mixer for industrial scientific medical (ISM) band direct conversion - zero IF receiver in 0.25-/spl mu/m CMOS is presented. The mixer uses a power efficient LO frequency generation scheme to overcome the LO self-mixing problems common in conventional direct conversion receivers (DCR). Simulated with 1% gm mismatch, 0.5% load mismatch and 2/spl deg/ LO phase error, the mixer is able to achieve 55 dBm of IIP2, -6.5 dBm of IIP3 and voltage conversion gain of 8 dB while consuming less than 1.75 mA from a single 3 V supply. The mixer also achieves input compression of -12 dBm and an overall double side band noise figure of 5.96 dB. The proposed mixer takes up less than 1 mm/sup 2/ of silicon real estate.

A compact 5.6 GHz low noise amplifier with new on-chip gain controllable active balun

A dual gain low noise amplifier for a 5.6 GHz ISM band direct conversion receiver, has been designed using a TSMC 0.25 /spl mu/m CMOS process and features a gain controllable on-chip active balun. The LNA provides gains of 19.5 dB and 12 dB in the two modes with 50% power savings in the low gain mode, while a noise figure of 3.1 dB and an IIP3 of -11.5 dBm have been achieved. A simple and novel gain control technique has been adopted and the gain control circuitry has been integrated with the balun.

A high IIP2 doubly balanced sub-harmonic mixer in 0.25-/spl mu/m CMOS for 5-GHz ISM band direct conversion receiver

This paper presents a new low power and high IIP2 0.25- /spl mu/m CMOS doubly balanced sub-harmonic mixer for a 5 GHz Industrial Scientific Medical (ISM) band direct conversion-zero IF receiver. Using a 1/2/spl times/LO frequency generation scheme, the sub-harmonic mixer, designed and fabricated, overcomes the LO self-mixing problem common in conventional direct conversion receivers (DCR). Measurements show the sub-harmonic mixer is able to achieve voltage conversion gain of 8.2 dB, input compression, P/sub 1dB/ of -8 dBm and IIP/sub 3/ of -2.5 dBm while consuming only 1.35 mA of DC current. Measured results correlate well with simulated results where with 1% g/sub m/ mismatch, 0.5 % load mismatch and 2/spl deg/ LO phase error, the mixer is able to achieve high IIP/sub 2/ of 55.3 dBm, IIP/sub 3/ of -6.5 dBm, and voltage conversion gain of 8 dB. The proposed mixer takes up less than 1 mm/sup 2/ of silicon real estate, including test die pads.

A new 0.25um CMOS on-chip active balun with gain controllability for 5GHz DCR [direct conversion receiver]

An on-chip active balun with good gain and phase mismatch performance of within 0.5 dB and 1 degree, respectively, is presented in this paper. Applicable for direct conversion receiver circuits, the presented balun features reconfigurability in the form of controllable gain, designed to operate in the 5-6 GHz range with a bandwidth of 400 MHz. With good linearity, input/output matching and gain and with improvement in noise performance, the proposed active balun circuit could effectively be used as the first stage of an RF front end replacing the LNA.

Low power and low phase noise 5.7 GHz LC VCO in OOK transmitter for neurosensory application

A 5.7 GHz fully integrated complementary LC voltage controlled oscillator (CLC VCO) has been designed in an inexpensive 0.25-/spl mu/m digital CMOS process for low power neurosensory application. Consuming only 2mA of current from a 2.5 V power supply, the CLC VCO achieves a measured single-sideband phase noise of -92.75 dBc/Hz and -97.6 dBc/Hz at 600 KHz and 1.0 MHz offset frequency, respectively. The CLC VCO is able to output -5dBm of power at the single-ended output to a 50-Ohm load to meet demands of high-date rate short reach on-off keying (OOK) wireless transmission. Various low power techniques used to improve phase noise in the LC VCO are also discussed.

A 5GHz LNA with new compact gain controllable active balun for ISM band applications

A low noise amplifier (LNA) with a new gain controllable on-chip active balun has been designed for a 5 GHz industrial scientific medical (ISM) band direct conversion receiver (DCR). The active balun provides good gain and phase matching with LNA gains of 19.5 dB and 12 dB in high gain and low gain modes, respectively, while achieving a noise figure of 3 dB and an IIP/sub 3/ of -11.5 dBm. In the low gain mode the LNA provides 50% power savings by using 15mW from a 3V supply.

Enhanced gm3 cancellation for linearity improvement in CMOS LNAs

An enhanced linearity improvement technique based on the third order intermodulation distortion cancellation or gm3 cancellation technique is presented in this paper. By identifying the issues related to the conventional gm3 cancellation method, the proposed technique is used to design a 0.18mum CMOS LNA using Jazz semiconductors BiCMOS process. With an IIP3 of more than +16dBm and gain of more than 15dB, the enhanced linearity LNA or EL2NA with a current consumption of 9mA from a 1.8V supply, provides an efficient way of improving linearity of 5G range direct conversion receivers

A 5 GHz novel 0.18-/spl mu/m inductor-less CMOS sub-harmonic mixer

A novel CMOS low voltage inductor-less sub- harmonic mixer for 5 GHz Industrial Scientific Medical (ISM) band direct conversion receiver in an 0.18-µm SiGe Bi-CMOS process is presented. Simulated with 0.5% gm mismatch, 0.5% load mismatch and 2o LO I/Q phase error the mixer is able to achieve high IIP2 of 43.6 dBm, IIP3 of 0 dBm, and voltage conversion gain of 8.05 dB while consuming less than 2.6 mA from a single 1.8 V supply. Index Terms — CMOS, direct conversion receiver (DCR), Hiperlan2, IEEE 802.11a, ISM band, linearity, mixer, RF CMOS, sub-harmonic mixer, Zero-IF receiver.

A 15-GHz single-pole double-throw annular MOSFET switch for space application

A high isolation 15-GHz radiation tolerant SPDT (single-pole double-throw) annular MOSFET switch, for space application, was designed and integrated in a SiGe BiCMOS process. Schwartz-Christoffel transformation, based on conformal mapping, and parasitic capacitance extraction methods were utilized to derive the equivalent circuit model of the octagonal annular MOSFET, which has demonstrated improved total dose radiation tolerance in CMOS circuits. The designed switch achieves 40.5-dB isolation at 15-GHz