This paper presents the x-band 5-bit MMIC digital attenuator with low phase shift. Phase compensation techniques were used in the MMIC design to reduce the phase shift. This attenuator is fabricated with 0.2μm GaAs PHEMT process. Measurement results of the developed MMIC chips in the xband show that the 5-bit MMIC digital attenuator has 0.5dB resolution and 15.5dB dynamic attenuation range, inp...

This paper presents results of a Ka-band VSAT Ground Terminal MMIC chipset developed in a cost reduction context. The first one, a Low Level Multifunction designed for up-conversion with high gain driver, exhibits a 17dB conversion gain with an associated P1dB output power close to +18dBm. The second one, a High Power Amplifier with embedded power detection, delivers 2W RF output power associat...

The cosmic microwave background (CMB) radiation is a major arena for testing cosmological theories. Its discovery confirmed the hot-bigbang origin of the universe and ruled out the steady-state theory. Since that time the impact on cosmology of CMB studies has grown steadily, indicating the prevalence of non-baryonic matter and the existence of a negative pressure component in the 1980’s; the d...

Heterostructure field-effect transistors (HFETs) composed of antimonide-based compound semiconductor (ABCS) materials have intrinsic performance advantages due to the attractive electron and hole transport properties, narrow bandgaps, low ohmic contact resistances, and unique band-lineup design flexibility within this material system. These advantages can be particularly exploited in applicatio...

A new type of compact microstrip line photonic band gap(PBG) structure employing T-type microstrip line for filter is presented. A miniature band rejection filter with four cells is simulated, fabricated, and measured. The filter with four proposed PBG structure exhibits band rejection characteristics (lower than -10dB from 23GHz~32GHz). The center frequency of stop-band is at 28GHz. The period...

A coplanar millimeter wave doubler MMIC covering the entire G-band was developed. Based on a 50 nm metamorphic HEMT technology, the circuit demonstrates an output power of more than –12 dBm between 150and 220 GHz for an input power of 0 dBm. By increasing the input power to 12 dBm an output power exceeding 0 dBm was obtained in the frequency range between 180and 220 GHz. Good fundamental reject...

This paper reports a novel MMIC balanced sub-harmonic cold FET mixer for MVDS applications using 0.15mm GaAs pHEMT. The mixer, which includes a LO buffer amplifier, was optimized for highly linear upconversion performance in the 42-43.5GHz RF band, 19.520.5GHz LO band and 2.45-3.45 GHz IF band. A dedicated simulation method has been developed to optimize conversion loss and determine optimum ma...

The need for a high-frequency and high-efficiency gallium nitride (GaN)-based buck converter that can be controlled directly by low swing pulse width-modulated (PWM) signal, without the additional buffers or preamplifiers, poses significant challenge in field of power conversion dynamically supply applications. To solve this problem, letter presents monolithic two-phase synchronous converter, f...

A method of fabricating horizontally aligned ZnO nanowire (NW) arrays with full control over the width and length is demonstrated. A cross-sectional view of the NWs by transmission electron microscopy shows a ‘‘mushroom-like’’ structure. Novel monolithic multisegment superstructures are fabricated by making use of the lateral overgrowth. Ultralong horizontal ZnO NWs of an aspect ratio on the or...

Inductors are a necessary building block in many circuits, including LNA and oscillators largely used in Receivers and various other systems. Because planer inductors can occupy a large amount of area in integrated-circuit (IC) designs, the search has been on for smaller, tunable inductors suitable for monolithic fabrication In this paper a method, which is to implement an active inductor by CM...