The power conversion efficiency of the rectifier mainly depends on the following: (i) series resistance of the diode ([R.sub.s]), which determines the efficiency of the rectifier; (ii) zero-bias junction capacitance
([C.sub.j0]) which affects the oscillation of harmonic currents through the diode; (iii) diode breakdown voltage, ([V.sub.br]), which limits the power-handling capability of the diode; (iv) switching speed of the diode which should be fast so that it can follow a high frequency signal; (v) and low threshold voltage so that it can operate at low RF input power .
To secure ZVS, energy stored on the primary inductor should be enough to charge and discharge the junction capacitance
of GaN HEMTs and other parasitic capacitance, shown as (8) and (9) for both primary side and secondary side, respectively.
The detector circuitry utilizes high performance GaAs Schottky Barrier Beam lead diodes with very low junction capacitance
. These detector designs perform with minimal sensitivity variation resulting in a flat frequency response across the entire waveguide band.
Lee, "Effect of junction capacitance
on the rise time of LED's and the turn on delay of injection lasers", Bell Syst.
where IS is the saturation current; RS is the ohmic resistance; BV is the reverse breakdown; IBV is the current at BV; CJO is the zero-bias junction capacitance
; M is the junction capacitance
grading exponent; N is the emission coefficient.
Similarly, in the off-state diode the junction capacitance
dominates, and a capacitance [C.sub.off] can model this impedance.
Fully compatible with digital transmission standards such as ADSL2 and ADSL2+, the SMP80MC family of micro-capacitance transient surge arrestors is the first TRISIL series for which the junction capacitance
does not depend on the device breakdown voltage.
While you can achieve the same thing more economically by putting multiple transistors in parallel, you would have a hard time achieving as low of junction capacitance
. The devices have a unity current gain frequency (the frequency that a piece of wire would do as well) of 40MHz.
The generation of sub-nanosecond pulses is mainly governed by the snap/transition time and junction capacitance
of an SRD.
The ESS technique is expected to lead to improved device performance by reducing junction capacitance
and suppressing short channel effects.