Some circuit design techniques for bipolar and MOS pseudologarithmic rectifiers operable on low supply voltage

Ultra-Wideband, Low-Power, Inductorless, 3.1–4.8 GHz, CMOS VCO

“…The circuit analysis when using bipolar devices is given in [10][11][12] (differential output) while it is proved that the differential output is free of the 1 st and 3 rd harmonic component. In [11], this principle is applied in a bipolar four-quadrant analog quartersquare multiplier and in [12], in a frequency mixer with a frequency doubler.…”

“…In [11], this principle is applied in a bipolar four-quadrant analog quartersquare multiplier and in [12], in a frequency mixer with a frequency doubler. MOS pseudologarithmic half-wave and full-wave rectifiers are presented in [10] based on the same principle. In [3,14] the circuit shown in Fig.…”

A Current‐mode Logarithmic Function Circuit

“…Thus, large values of b would be preferable. Alternatively, many measures can be taken to minimize the effect of finite bs on the performance of the circuit of Figure 1 [8].…”

“…This justifies the continuing interest in developing logarithmic function circuits manifested by the relatively large number of publications in this area; see for example Refs. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and the references cited therein. Traditionally, a logarithmic function circuit, with input voltage and output voltage (or current) can be realized by exploiting to advantage the inherent exponential transconductance characteristic of the pn junction in a diode [12], bipolar transistor [5], or LED [16], to introduce the required nonlinearity into a circuit based on a current-feedback-operational [12], a transimpedance-amplifier [19], an operational-amplifier [1,16], a transconductance-feedback-amplifier [18], or a current-conveyor [13].…”

“…Alternatively, a pseudo-logarithmic function can be implemented using piecewise linear approximations and cascaded limiting amplifiers [6]. This logarithmic function can be realized in GaAs hetrojunction bipolar transistor (HBT) technology [2,3], GaAs MESFET technology [4,15], bipolar, CMOS or BiCMOS technology [8][9][10][11]14]. On the other hand, current mode circuits, with current inputs and current outputs, enjoy the attractive features of a wide current signal dynamic range even with low power supply voltages and wide bandwidths.…”