Papers by Keyword: CPW

Abstract: In this paper, based on the design theory of CPW equalizer with low VSWR, microwave reconfigurable equalizers with various equalization curves have been designed. The combined structures of the reconfigurable equalizer with low VSWR and small sizes via MEMS switches have been optimized by ADS and HFSS software. The equalizer can be used in the frequency range from 20GHz to 24GHz. With the control of switches, the reconfigurable equalizer can realize the variation of the equalization curves and achieve the minimal insertion losses of around-1dB, respectively. In order to improve the minimal insertion losses, a matched structure has been presented. The matched structure reduces the minimal insertion losses compared with the former structure significantly.

Abstract: Tunable bandpass filters are generally preferred and are used extensively in the mobile communication systems. In this paper, a design of the RF MEMS tunable combline bandpass filter is proposed. Firstly, the theory of the RF MEMS tunable combline bandpass filter is presented. Secondly, a combline bandpass filter which have a tunable frequency range from 18GHz to 27GHz is designed and simulated by using the EDA simulation software. Its bandwidth is about 1GHz in the tunable frequency range. From the simulation results, the designed filter is not only compact and effortless to fabricate but also relatively superior in some aspects.

Abstract: In this paper, fully monolithic tunable millimeter-wave filters using defected ground structures (DGS) are proposed using the CPW-based periodic structures with novel multiple-contact MEMS switches. Millimeter-wave low-pass filters were designed, fabricated, and tested. The cascaded CPW-based periodic structures, with low-pass intrinsic filtering characteristics, are reconfigured into a self-similar single unit cell by the operation of the novel multiple-contact MEMS switches with single actuation. In the first order tuning, the 3-dB cut-off frequency changes from 8.2GHz to10.5GHz, and the second order tuning is 8.2GHz to 16.8GHz. The tested results show that the pass-band ripple is less than 1.2dB and the maximal out-of-band rejection is better than 27dB. The chip size of the low-pass filter is 2.5mm×1.2mm.

Abstract: This paper presents a novel MEMS coplanar microwave waveguide (CPW) structure. The high-resistivity silicon is chosen as the material of substrate and the aluminum is as the metal transmission line because of its high conductivity ,Removing the silicon between the signal line and ground line, underneath the edge of both line,these can effectly reduce the loss.A layer of polyimide is added between the metal and silicon substrates continued to reduce the loss. The simulation results from HFSS show and demonstrate the insert loss is less than the results of traditional CPW.

Abstract: As the requirement for the low loss phase shifter increases, so does the development of RF MEMS as a solution. This paper presents the design & simulation of Switched line MEMS phase shifter for Ku band using GaAs substrate. The phase shift can be achieved by varying the lengths in delay path to the reference path for the same phase velocity. The electromagnetic & electromechanical simulations were carried out with various structural parameters to optimize the design. The novelties like low insertion loss, low actuation voltage with distributed actuation pads for DC and RF are used to make the design unique. The EM simulations are carried out using 3D simulator HFSS and a phase shift of 172.6 deg./dB for a total Phase shift of 348.75deg was achieved with return loss of 15.5dB over a frequency band from 16-18 GHz and a phase shift error less than ±2 degree in the 32 states. The electromechanical simulations are carried to achieve the low actuation voltage of 15.3V. These parameters make these suitable for the Phased array applications [1, 2].

Abstract: A novel low-profile reconfigurable CPW-fed slot antenna that is designed using a half-wavelength slot-line resonator is proposed in this paper. Frequency hopping can be easily achieved by incorporating a pair of PIN diodes, being controlled in either their on or off state. Benefited from the magnetic current distribution of a half-wavelength slot-line resonator, the radiation patterns at the two operating frequencies (1.8GHz and 2.45GHz) are very stable, being almost identical. The proposed antenna is designed and fabricated, and the theoretical and measured results are presented and show good agreement.

Abstract: The design and development of novel microelectromechanical systems’ (MEMS) coplanar waveguide (CPW) transmission lines, using microshield and groove, are presented in the paper to operate between 5–60 GHz. The quasi-static capacitances of CPW are calculated using the conformal mapping technique to express the propagation properties, i.e., the characteristic impedance and effective permittivity. Simulation results have shown a considerable loss reduction to levels that compare favorably with the conventional CPW. These transmission lines can be widely used in the development of phase shifters, filters, and antennas, because of their advantages in loss reduction and improvement in the performance.

Abstract: In this paper, a novel micro-wave band-stop filter using coplanar-waveguide (CPW) and a parameters extraction method based on Schwarz transformation are presented, The experimental results show excellent agreement between the extracted performance of equivalent circuit and the simulation performance of filter model.