Fabrication of QFN-Packaged Miniaturized GaAs-Based Bandpass Filter with Intertwined Inductors and Dendritic Capacitor

Abstract

This article presents a compact quad flat no-lead (QFN)-packaged second-order bandpass filter (BPF) with intertwined inductors, a dendritic capacitor, and four air-bridge structures, which was fabricated on a gallium arsenide (GaAs) substrate by integrated passive device (IPD) technology. Air-bridge structures were introduced into an approximate octagonal outer metal track to provide a miniaturized chip size of 0.021 × 0.021 λ0 (0.8 × 0.8 mm2) for the BPF. The QFN-packaged GaAs-based bandpass filter was used to protect the device from moisture and achieve good thermal and electrical performances. An equivalent circuit was modeled to analyze the BPF. A description of the manufacturing process is presented to elucidate the physical structure of the IPD-based BPF. Measurements were performed on the proposed single band BPF using a center frequency of 2.21 GHz (return loss of 26.45 dB) and a 3-dB fractional bandwidth (FBW) of 71.94% (insertion loss of 0.38 dB). The transmission zero is located at the 6.38 GHz with a restraint of 30.55 dB. The manufactured IPD-based BPF can play an excellent role in various S-band applications, such as a repeater, satellite communication, and radar, owing to its miniaturized chip size and high performance.

Design and Micro-Nano Fabrication of a GaAs-Based On-Chip Miniaturized Bandpass Filter with Intertwined Inductors and Circinate Capacitor Using Integrated Passive Device Technology

“…The loss resistance in the inductor (L) and capacitor (C) including the resistance caused by proximity effect, are denoted by R L and R C , respectively [ 4 ]. R Sub and C Sub represent the resistance and capacitance associated with the substrate whereas C SiNx represents the capacitance of the SiN x passivation layers.…”

“…In the past few decades, several manufacturing technologies, such as monolithic microwave integrated circuits (MMICs), microelectromechanical systems (MEMSs), low-temperature co-fired ceramics (LTCCs), and high-temperature superconductors (HTSs), have been widely studied to meet the growing market demand [ 4 ]. The LTCC technology embeds several passive components (such as resistors, capacitors, and inductors) in ceramics through punching, grouting, and printing, which reduces the size of the entire module.…”

Integrated Passive Device-Based Gas Sensor Combined with PANI/SnO2 Composites for Ammonia Detection

“…A SnO 2 /bionic porous (BP) carbon composites-based thick film material is prepared, and an ultra-narrowband microwave filter based on microwave transmission technology is designed to verify the sensing performance of ammonia at room temperature . In other fields of microwave sensor technology, the low-temperature co-fired ceramic and substrate-integrated waveguide also have been used in research on gas sensing, but in the field of IPD technology, a large number of studies devoted to the development of filters, detections of biological solutions, investigations of environmental humidity, characterizations of dielectric materials, construction of diplexers and dividers, there are few reports about gas sensors based on integrated passive device (IPD) technology. The IPD-based microwave sensor exhibits higher microwave performance by using a lower loss GaAs substrate, more complex design structures and micro–nano processing technology, small size, and easy integration compared to the planar microwave devices.…”

Comparison of Different Large Signal Measurement Setups for High Frequency Inductors

“…There has been a significant number of reports on large signal characterization of discrete passive devices. In the particular case of characterization of inductors, there is an increasing interest because of the thin film components working in Power Supply on Chip or Power Supply in Package [1][2][3][4][5][6][7][8]. These kinds of applications present two main challenges regarding the measurement: (1) the high frequency (above 10 MHz) and (2) the high Q of the component (very small resistance compared to its reactance).…”