A novel compact and highly efficient SIW antenna has been proposed. Size reduction was achieved using an EMSIW cavity. The proposed aperture size is only 12.5% of the size of the SIW cavity. It resonates at 4.54 GHz with 1.8% of the 10 dB bandwidth. At 4.54 GHz, the peak gain is 5.83 dBi, and the radiation efficiency is 96%. In spite of the compact size, high gain and efficiency are achieved because of the two open sides of the EMSIW antenna. The proposed antenna is a good candidate for portable wireless devices which require compact size and high efficiency.ACKNOWLEDGMENT

No abstract

A load network for zero voltage switching high efficiency power amplifier design consisting of a parallel coupled line has been demonstrated. The load network was able to present the terminations required for a zero voltage switching class‐E power amplifier load topology. Simulated time domain voltage and current waveforms for the designed power amplifier at the transistor output terminal proved the workings of the proposed load network topology. The fabricated power amplifier designed at 1.2 GHz with the proposed load network was measured with different levels of input rf power. At the designed input rf power of 30 dBm, the power amplifier recorded an output power of 42 dBm with a power added efficiency of 67%. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2926–2929, 2014

A modular approach to design full three‐way active circulator is presented. Derived S‐parameters for the modular design approach illustrates that broadband performance can be achieved with broadband performance modules. A full three‐way 8 to 18 GHz MMIC active circulator was designed and fabricated with broadband feedback amplifiers and broadband 180° hybrids. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2858–2861, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27202

Monolithic microwave integrated circuits (MMICs) have become an important and integral part of our lives today. Modern day MMICs can be found in a wide range of applications ranging from commercial products such as the cellular communication systems to complex satellite systems and radar systems used in the defence industries. The advancement in the field of MMICs in terms of its performance and compactness in size is the result of the union between the understanding in microwave/millimeter-wave frequencies theories and microelectronics fabrication competencies. The active device which is the key component for MMICs has seen tremendous progress over the past fifty years not solely in terms of the frequency of operation but also the achievable output power density [1]. For example, indium phosphide (InP) based double heterojunction bipolar transistors had demonstrated a f max of greater than 800 GHz [2], silicon germanium (SiGe) and CMOS based RFICs working above 100 GHz [3], and AlGaN/GaN based power amplifiers operating in the W-band frequency spectrum [4],[5]. A GaN power amplifier design capable of achieving pulsed output power of greater than 400W with PAE greater than 40% across the frequency range from 2.9 GHz to 3.5 GHz was demonstrated [6]. GaN power amplifier capable of achieving pulse output power of 750W was also demonstrated but has a narrow bandwidth performance at 2.14GHz [7].As listed above, each material will have traits superior to others and selecting the appropriate material system to be used in circuit design will depend on the intended application. Certain materials such as InP and GaAs are more proficient in high frequency operation (beyond w-band operation) while material such as GaN display superiority when used in high power applications.