Eric Main

A linear Class AB single-ended to differential transconverter suitable for RF circuits

A novel circuit topology is presented which converts a single-ended signal into differential output currents with improved linearity. This cell operates in class AB, allowing an output current greater than the quiescent current. A configuration which allows for the nulling of the third order distortion is derived and the implications of third order nulling on third order intermodulation is explained. Measured results of this cell implemented in 0.4 /spl mu/m silicon-bipolar technology is presented.

FM demodulation using an injection-locked oscillator

An injection-locked oscillator in combination with a phase detector is shown to make a very effective FM demodulator. The dynamic behavior is similar to a PLL but with several advantages, one of which allows automatic tuning from outside the locking range.An injection-locked oscillator in combination with a phase detector is shown to make a very effective FM demodulator. The dynamic behavior is similar to a PLL but with several advantages, one of which allows automatic tuning from outside the locking range.

An FSK demodulator for Bluetooth applications having no external components

An injection-locked oscillator in combination with a phase detector is shown to make a very effective frequency-shift keying (FSK) demodulator for Bluetooth applications. The dynamic behavior allows automatic tuning from outside the locking range. Two tuning methods are described which eliminate the need for external components, allow fast tuning and can handle low-frequency data. A cancellation technique is used which minimizes filtering requirements. The demodulator was fabricated in a bi-complementary metal-oxide-semiconductor (BiCMOS) technology with L/sub eff/ = 0.25 /spl mu/m. The die area was 0.09 mm/sup 2/ and the current consumption was 0.8 mA with a supply voltage of 2.8 V.

Effects of offsets on bipolar integrated circuit mixer even order distortion terms

Second order intermodulation products and other spurions signals in bipolar double-balanced mixers can be generated due to device mismatches. The creation of these spurs is analyzed theoretically and by simulation. Guidelines are presented that show the maximum acceptable mismatch to meet a given spurious rejection specification.