Return loss

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

A novel CPW-fed wideband printed monopole antenna with DGS

Abstract: This paper presents a novel printed monopole antenna with defective ground structure for worldwide interoperability for wireless communication. The basic design comprises of a monopole patch with co-planar ground plane which exhibits the impedance bandwidth ( S 11 ≤ −10 dB) of 3.18 GHz (from 3.32–6.50 GHz) and the peak gain throughout the frequency band is 4.5 dB. The initial design is further modified to enhance the impedance bandwidth and gain by employing a defective ground structure in the co-planar ground plane of the monopole patch. The measured bandwidth for return loss S 11 ≤ −10 dB is 2.44–2.58 GHz and 3.5–8.85 GHz which cover all the WLAN (2.4/5.2/5.8 GHz) bands, WiMAX (2.5/3.5/5.5 GHz) bands and point to point (5.925–8.5 GHz) high speed wireless applications as per ECC and FCC frequency standards. The experimental and simulated results of a novel CPW-fed (co-planar waveguide) printed monopole antenna with DGS (defective ground structure) are reported here.

A novel RF MEMS switch on frequency reconfigurable antenna application

Abstract: This paper presents the design, analysis, simulation of a novel radio-frequency micro electromechanical system (RF MEMS) switch on the frequency reconfigurable antenna application. The switch uses coplanar waveguide transmission line for signal transmission, which designed with special mechanical structures, the size of the switch beam is 320 × 120 μm2. The design of RF MEMS switch was simulated using ANSYS. Its simulation voltage is 14 V for 1 µm beam thickness. The electromagnetic performance is optimized and computed by ANSYS EM software. The switch working bandwidth is 40 GHz, the insertion loss is 0.1 dB, return loss of 30 dB and isolation of 26 dB over 30 GHz. In the frequency band, the isolation degree more than 15 dB, and the maximum isolation is 45.3 dB. The switch is mounted on the antenna, and the frequency of the antenna can be reconstructed by using ANSYS EM simulation.

Multioctave bandwidth log-periodic microstrip antenna array

Abstract: The application of the log-periodic technique to the series-fed electromagnetically coupled overlaidpatch array allows antennas with flat conformal characteristics and wide bandwidths to be obtained. A k-s analysis of this and other microstrip array types indicate that the microstrip patch is not an optimum element for log-periodic arrays and that direct connection will result in arrays having a limited bandwidth. The addition of series capacitance to the patch equivalent circuit, implemented by electromagnetic coupling, allows an optimum to be approached. Log-periodic overlaid patch array design and measured results for an array with a 4:1 bandwidth are presented. These, together with a transmission-line analysis, indicate the array-design trade offs available and that the ultimate bandwidth is limited primarily by changes in the input return loss and radiation pattern due to the use of uniform thickness substrates.

Millimeter-wave wideband transition from CPW to substrate integrated waveguide on electrically thick high-permittivity substrates

Abstract: A wideband transition from coplanar waveguide (CPW) to substrate integrated waveguide (SIW) is proposed and presented in the 50 GHz frequency range. Electrically thick alumina was used in this case, representative for other high-permittivity substrates such as semiconductors. Simulations predict less than -15 dB return loss within a 35 % bandwidth. CPW probe measurements were carried out and 40 % bandwidth were achieved at -0.5 dB insertion loss for a single transition. Modified SIW via configurations being suitable for simplified fabrication on electrically thick substrates in the upper millimeter-wave spectrum are discussed in the second part.

Substrate integrated waveguide dual-mode filters for broadband wireless systems

Abstract: A planar dual-mode filter on the basis of the substrate integrated waveguide (SIW) technique has been proposed and developed. Microstrip probes are used to excite two modes in an SIW cavity. These modes cancel each other at one frequency to create a transmission zero. Parametric influences in the filter design have been studied. A 26 GHz dual-mode filter has been designed, fabricated and measured. The insertion loss of 0.5 dB is obtained at the center frequency. The return loss is lower than 15 dB.