Due to the low impedance at the base, high transconductance, and output resistance compared to MOS devices, the BJT is characterized as current-controlled current source useful to compute nonlinear functions by their logarithm dependence between base-emitter voltage [V.sub.BE], collector current
[I.sub.C], and temperature, which recently has led to its integration into the CMOS-based architectures [5-8].
In this technique, a resistor is implemented at the base or emitter of a HBT to prevent the collapse of the collector current
in the event one of the HBT unit cell operates at a higher temperature -.
Assuming a voltage signal of the form [V.sub.be1](t) = [V.sub.b] + [V.sub.LO]cos([[omega].sub.LO]t) + [V.sub.rf]cos([[omega].sub.RF]t) across the base-emitter junction of [Q.sub.1] the collector current
[I.sub.c1] for this HBT can be represented as
The collector current
changes significantly with the total dose.
These new devices are rated at 1.0 A of continuous collector current
, 25-V collector-to-emitter voltage, and have an energy efficient low VCE(SAT) of 25 mV for NPN and 30 mV for PNP.
The output current signal is generated by the variation of collector current
, caused by induction [B.sub.[perpendicular to]].
* An on-state collector current
that varies from 1 (min) to 6 mA (max).
Digital Display Monitors: Collector Current
, Collector Voltage, Helix Current, Helix Voltage, Forward RF Power, Reflected RF Power, Filament Hours, Beam Hours
After the first base current is set, the collector voltage is swept while the collector current