Return loss

About: Return loss is a research topic. Over the lifetime, 11090 publications have been published within this topic receiving 97603 citations.

Miniaturized DC–60 GHz RF PCM GeTe-Based Monolithically Integrated Redundancy Switch Matrix Using T-Type Switching Unit Cells

Abstract: This article presents an approach to monolithically implement radio-frequency (RF) phase change material (PCM) germanium telluride (GeTe) T-type switch as a switching unit cell for millimeter-wave (mmWave) redundancy switch matrix applications. The miniature T-type switch demonstrates three states of operation, including one crossover state and two turn states. A seven-layer microfabrication process, including an additional conductive layer to reduce the $RC$ time constant due to the bias network routing, is developed and optimized to fabricate the multiport RF devices. A $4 \times 6$ PCM-based redundancy switch matrix is developed by monolithically integrating four T-type switches in the cascade configuration. Thermal crosstalk in PCM switches is experimentally investigated using submicrometer spatial resolution transient thermal imaging. The presented T-type switch has the device periphery of 0.55 mm $\times \,\,0.55$ mm, while the overall integrated PCM redundancy switch matrix is fabricated with a device footprint of 0.88 mm $\times \,\,1.1$ mm. The measured results of the T-type switches demonstrate an excellent RF performance with lower than 1.6 dB insertion loss, better than 20 dB return loss, and higher than 20 dB isolation in all states from dc–67 GHz. The redundancy switch matrix exhibits an insertion loss less than 3 dB, return loss better than 14 dB, and isolation higher than 20 dB from dc–60 GHz. To the best of our knowledge, this is the first implementation of a PCM-based redundancy switch matrix.

Millimeter-Wave Frequency Doubler With Transistor Grounded-Shielding Structure in ${\hbox {0.13-}}\mu{\hbox {m}}$ SiGe BiCMOS Technology

Abstract: A low conversion-loss monolithic frequency doubler has been developed for D-band signal generation in 0.13-μm SiGe BiCMOS technology. The circuit uses a single-transistor topology with a novel grounded-shielding structure, which can efficiently reduce the parasitic feedback effect between collector and base of a HBT to achieve frequency multiplication. The measurement results show that the doubler exhibits minimum ~3.2-dB conversion loss at the output frequency of 134 GHz with the efficiency of ~5.8% and maximum -1.4-dBm second-harmonic output power at the output frequency of 132 GHz with the efficiency of ~7%, respectively. Moreover, both input and output return loss are better than 10 dB for the input frequency from 64 to 69 GHz and the corresponding doubled output frequency range. In addition, the estimated rejection of the fundamental signal is better than 20 dB.

Surface wave enhanced broadband planar antenna for wireless applications

Abstract: This letter explores the development of a new class of broadband antenna in which TE/sub 0/ surface-wave is used as the primary source of free space radiation. We demonstrate that antennas based on this concept can be designed to operate over a broad bandwidth, be extremely compact, and can be easily integrated with MIC and MMIC technology. Measurement of return loss and radiation pattern characteristics of the antenna described in this letter indicate a 47% operating bandwidth, covering a large part of the frequency spectrum assigned for U.S. as well as European high-speed wireless local area network (WLAN) applications, making it ideal for integration with WLAN modules.

Broadband Modified Rectangular Microstrip Patch Antenna Using Stepped Cut at Four Corners Method

Abstract: In this paper, a new method that called the Stepped Cut at Four Corners is introduced to design a multi-mode/broadband modified rectangular microstrip patch antennas (MRMPAs). In order to become acquainted with the new method, the design process of a monopole broadband MRMPA suitable for multifunctional wireless communication bands is explained. The methodology of the proposed broadband MRMPA design is presented in six stages. The first stage is designing a single-mode RMPA. Subsequently, by creating a step at the corners using the proposed method a dual-mode antenna is obtained at the second stage, while the triple-mode and multi-mode antennas are designed, at the third and fourth stages respectively. Two types of broadband antennas are obtained, the stepped line and straight line antennas. By increasing the number of steps, the antenna's operating bandwidth (BW), with return loss less than -lOdB, covers the frequency range from 900 MHz to 2.6 GHZ, which is suitable for GSM (900 MHz and 1.5 GHz), WiFi (2.4 GHz) and LTE (2.6 GHz) applications. In addition, the antenna prototype has been fabricated and measured in the all stages, in order to validate the simulation results, and there is a close agreement between the simulated and measured results

A 3-D X-Band T/R Module Package With an Anodized Aluminum Multilayer Substrate for Phased Array Radar Applications

Abstract: This paper presents the design and development of a compact 3-D transmit/receive (T/R) module with a selectively anodized aluminum multilayer package for X-band phased array radar applications. The proposed multilayer package consists of anodized aluminum substrates and vertical interconnects with embedded vias. The proposed package platform is based on thick anodized aluminum oxide layers and active bare chips directly mounted on bulk aluminum substrates for high electrical isolation and an effective heat sink. With its combination of thin-film embedded passive components and multilayer structure, the proposed module features a compact size of 20 mm × 20 mm, with a package height of 3.7 mm. To transfer radio-frequency (RF) signals vertically, we used coaxial hermetic seal vias with characteristic 50 Ω impedances and embedded anodized aluminum vias with a solder ball attachment and flip-chip bonding. The optimized vertical interconnect structure demonstrates RF characteristics with an insertion loss of less than 1.55 dB and a return loss of less than 12.25 dB over a broad bandwidth ranging from 0.1 to 10 GHz. The fabricated X-band 3-D T/R module has a maximum transmit output power of 39.81 dBm (9.5 W), a maximum transmit gain of 41.25 dB, and a receive gain of 19.15 dB over the 9-10 GHz frequency band. The RF-signal phase amplitude control is achieved by means of a 6 bit phase shifter with an rms accuracy of more than 5° and a gain setting range of 24 dB with an rms accuracy of more than 1.5 dB. The proposed multilayer aluminum package has the advantages of reducing the module size, decreasing the cost, and managing the thermal problem for X-band high-power T/R module package applications.