Title :
Frequency-scalable SiGe bipolar RF front-end design
Author :
Shana, Osama ; Linscott, Ivan ; Tyler, Len
Author_Institution :
Dept. of Electr. Eng., Stanford Univ., CA, USA
fDate :
6/1/2001 12:00:00 AM
Abstract :
The optimum collector current density, at the global minimum noise figure (NF) point for a bipolar transistor, scales linearly with frequency. The optimum source impedance, on the other hand, remains constant if the device area is scaled inversely with frequency. As a result, transforming the design from one frequency to another can be achieved by simple circuit scaling. Taking advantage of the shallow nature of the NFmin global minima, it is possible to increase the linearity of the low-noise amplifier (LNA) or decrease its power consumption, which is required for multimode designs, with little degradation in NF. These theoretical results have been applied to LNA and active mixer designs, and verified by constructing a 1.8-GHz frequency-scaled SiGe bipolar test chip. The measured LNA NF is 1.3 dB at 4.5 mA, while the double-balanced mixer achieves a single-sideband (SSB) NF of 6.1 dB for the low-linearity mode and an IIP3 and an SSB NF of +3 dBm and 6.6 dB, respectively, for the high-linearity mode
Keywords :
Ge-Si alloys; UHF amplifiers; UHF integrated circuits; UHF mixers; bipolar analogue integrated circuits; current density; integrated circuit noise; semiconductor materials; 1.3 dB; 1.8 GHz; 4.5 mA; 6.1 dB; 6.6 dB; LNA; SiGe; active mixer designs; bipolar RF front-end design; circuit scaling; collector current density; device area; double-balanced mixer; global minimum noise figure; high-linearity mode; linearity; low-linearity mode; multimode designs; optimum source impedance; power consumption; single-sideband NF; Amplitude modulation; Bipolar transistors; Circuits; Current density; Germanium silicon alloys; Impedance; Noise figure; Noise measurement; Radio frequency; Silicon germanium;
Journal_Title :
Solid-State Circuits, IEEE Journal of
