Hysteresis current control method is vastly used in PWM inverters because of simplicity in performance, fast control response and good ability in limiting peak current. However, switching frequency in hysteresis current control method with fixed bandwidth has large variation during a cycle and therefore causes non-optimal current ripple generation in output current. One of basic problems in imp...

GSM & EDGE base-stations require synthesizers that can frequency hop over the full 75MHz TX or RX band in < 10us and also have very low phase noise and spurious. To date, these conflicting requirements can only be accomplished using a costly "ping-pong" architecture where one synthesizer is locking to the next desired frequency while the other is active as the LO. The proposed fast switching sy...

On-line pulsewidth modulation (PWM) pattern generators for current–source rectifiers and inverters offer a number of control advantages over off-line optimized patterns. However, when implemented using the principles which apply to voltagesource inverter PWM pattern generators, the switching frequency is equal to: 1) the carrier frequency in standard carrier-based implementations and 2) a funct...

We have switched GaAs/AlAs and AlGaAs/AlAs planar microcavities that operate in the "Original" (O) telecom band by exploiting the instantaneous electronic Kerr effect. We observe that the resonance frequency reversibly shifts within one picosecond when the nanostructure is pumped with low-energy photons. We investigate experimentally and theoretically the role of several parameters: the materia...

Frequency Reconfigurable antennas have received significant attention for their applications in communications, electronic surveillance and countermeasures, by adapting their properties to achieve selectivity in frequency, bandwidth, polarization and gain. This paper presents the design of reconfigurable conformal antenna for wireless LAN networks. The proposed antenna is suitable for Wireless ...

In this paper, a DC-DC resonant converter with high voltage gain and small size is studied. To reduce the size and weight of this converter, the operating frequency should be as high as possible. In this research, the frequency changes from 120 to 200 kHz. Due to the high operating frequency, it is necessary to reduce the switching losses using soft switching methods. Resonant converters are su...

In this paper, a DC-DC resonant converter with high voltage gain and small size is studied. To reduce the size and weight of this converter, the operating frequency should be as high as possible. In this research, the frequency changes from 120 to 200 kHz. Due to the high operating frequency, it is necessary to reduce the switching losses using soft switching methods. Resonant converters are su...

Abstract A reconfigurable tri/quad-band resonator and the application to band-pass filter have been demonstrated. By changing switching state of PIN diodes, can work in tri-band mode or quad-band mode. Correspondingly, resonant frequencies are 1.21 GHz, 2.0 3.23 1.27 2.61 3.41 respectively. Especially, has a combined structure lumped capacitors some transmission lines achieves small mechanical ...