It is obvious that the CPS current feeding the EMAT can not instantaneously bring into operation the parallel resonant circuit
of the electromechanical transducer.
The reduction of the inverter network is based on the assumption close to the real case that the output voltage of the inverter appearing across the load inductor and the connected in parallel output capacitor (namely the output parallel resonant circuit
) is practically with a sine-wave shape due to the relatively high quality factor of the output inverter circuit.
New machines use metal oxide silicon, field-effect transistors (MOSFET), often associated with parallel resonant circuit
. The constant voltage version generators use insulated gate bipolar transistors (IGBT) designed to power about 2,000 kW with frequency ranges of 100-600 kHz.
When the width of DGS is increased, the cut off frequency of the parallel resonant circuit
in equivalent circuit decreases, and because c2 has same value, the lower stop frequency does not change significantly.
This circuit model which composed of a series resonant circuit and a parallel resonant circuit
helps the analysis of the dual resonance performance of the antenna .
Loaded quality factor of the parallel resonant circuit
at the resonant frequency is
In relation to the prototypes designed later on we see that a slot antenna can be treated as a band pass filter which consists of a parallel resonant circuit
Because a parallel resonant circuit
was used, the separation distance was smaller and the impedance lower.
Obviously, the shunted C1 in parallel with the unloaded parallel resonant circuit
will cause the coupled resonant frequency to be lower than the unloaded one.
When the DGS serves as a resonant circuit, the parallel resonant circuit
in the equivalent circuit of the DGS is combined with the parallel eapacitance, [C.sub.p1].
The second step in the design of the broadband input matching circuit requires the use of a parallel resonant circuit
to cancel the reactive part of both of the hand edge impedances.
The device is assumed to represent a fixed negative resistance and the resonator is a simple series or parallel resonant circuit
with some finite Q.