Return loss

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

Communications connectors having crosstalk stages that are implemented using a plurality of discrete, time-delayed capacitive and/or inductive components that may provide enhanced insertion loss and/or return loss performance

Abstract: Communications connectors include a plurality of “discrete” elements to implement the capacitive and/or inductive components of offending and/or compensatory crosstalk stages. By sub-dividing the crosstalk stages into a plurality of time-delayed discrete elements improved return loss and insertion loss may be achieved for very high frequency signals, without having a substantial impact on the crosstalk performance of the connector.

Design of Microstrip-to-Microstrip Via Transition in Multilayered LTCC for Frequencies up to 67 GHz

Abstract: A wide-band microstrip-to-microstrip via transition proposed for connecting an integrated circuit chip and an antenna array on the opposite sides of a multilayered low-temperature co-fired ceramic substrate is investigated in this paper. To facilitate the design, it is decomposed into external and internal segments, which consist of two microstrip-to-via transitions and a multilayered through-hole via with four ground vias, respectively. The equivalent impedance of the internal segment is carefully calculated from the lump-circuit model extracted by Ansoft Q3D, and verified by high-frequency structure simulation (HFSS). The S-parameters of external segments are simulated by HFSS for impedance matching, thereby obtaining the appropriate physical parameters. The physical mechanisms that result in the insertion loss are explored in detail, and the effects of via diameter are also investigated for the reduction of insertion loss. By combining the designs of the external and internal segments, the simulated S-parameters demonstrated that the overall return loss level was above 20 dB within 57-67 GHz spectrum and insertion loss was better than 0.48 dB from d.c. up to 67 GHz. Coherent results between simulation and measurement were also obtained with a back-to-back transition structure.

Compact wide tri-band slot antenna for WLAN/WiMAX applications

Abstract: A compact wide tri-band microstrip-fed slot antenna for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) application is presented. Three operating bands are achieved by inserting a pair of T-shaped strips into a wide rectangular slot. The bandwidth enhancement is obtained by introducing a staircase pattern into the wide rectangular slot. A fabricated prototype for the proposed tri-band antenna has compact dimensions of 36×30×mm 2 , and provides a wide impedance bandwidth. The measured impedance bandwidth for 10dB return loss at 2.5, 3.5, and 5.6 GHz operating band can be up to 540, 940, and 950 MHz, respectively. Moreover, the antenna shows monopole-like radiation patterns and stable antenna gains across the three operating bands.

A Compact Broadband Antenna with an L-Shaped Notch

Abstract: A small microstrip-fed monopole antenna using an L-shaped notch is presented for ultra wideband applications. The proposed antenna, with compact size of 15.5 x 21 mm 2 including the ground plane, is designed to operate over the frequency band between 3.05 and 10.9 GHz for S 11 < -10 dB. Good return loss and radiation pattern characteristics are obtained in the frequency band of interest.

A Highly Reconfigurable Low-Power CMOS Directional Coupler

Abstract: This paper presents a highly reconfigurable, low-power, and compact directional coupler. The coupler uses varactors and novel active inductors to achieve wide tuning ranges of operating frequencies and coupling coefficients. The use of a low-pass circuit architecture with only two inductors minimizes chip area, power consumption, and noise. The coupler is implemented in a 0.13-μm CMOS process. It occupies an area of 350 μm× 340 μm and consumes 40 mW or less power. The obtained 1-dB compression point is -3.2 dBm, and the measured noise figure is ~ 23 dB. These parameters compare favorably with previously published reconfigurable couplers. The measured coupling coefficient can be tuned from 1.3 to 9.0 dB at 4 GHz with 32 dB or better isolation and 15 dB or better return loss. The operating center frequency can be tuned from 2.0 to 6.0 GHz for a nominal 3-dB operation. These results agree with theoretical predictions and simulations reasonably well.