Reconfigurable Slot Research Articles

Investigation of the S-PIN Diodes for Silicon Monolithic Antennas With Reconfigurable Aperture

Investigations of surface p-i-n (S-PIN) diodes developed for silicon monolithic antennas with reconfigurable aperture have been described. The main criteria for choosing a suitable substrate for the S-PIN diodes have been extensively discussed. Based on this analysis, it has been found that dedicated silicon-on-insulator (SOI) substrates meet the requirements of efficient and lossless wave propagation. Experimental results shown in this paper confirm the applicability of SOI substrates for manufacturing of electrically reconfigurable slot apertures. The results show that S-PIN diodes realized on SOI substrates are suitable for various microwave and millimeter-wave applications.

A Reconfigurable Radial Line Slot Array (RLSA) Antenna for Beam Shape and Broadside Application

A reconfigurable beam shape and broadside radiation pattern microstrip antenna is introduced in this paper. The antenna's radiating surface is designed using a radial line slot array (RLSA) arrangement, which is fed from an aperture coupled structure. This novel feeding structure for an RLSA antenna incorporates PIN diode switches which are integrated with the feed line structure to enable the various outcomes of the radiation patterns. The circular arrangement of slots at the radiating surface contributes to the reduction in size of the proposed antenna compared to conventional microstrip antenna that can yield the same antenna gain. The proposed antenna design operates at 2.3 GHz frequency band and has a maximum gain of 14.64 dB. It also produces a broadside radiation pattern with a wider beamwidth covering from −85° to 85° compared to the conventional microstrip antenna which could only cover from −50° to 50°. The proposed antenna has an enormous potential for point-to-point and point-to-multipoint communication, WiMAX, and radar application.

A Novel Switchable Single- and Multifrequency Triple-Slot Antenna for 2.4-GHz Bluetooth, 3.5-GHz WiMax, and 5.8-GHz WLAN

A novel reconfigurable slot antenna with three switchable frequencies is presented. The uniqueness of this design is that it allows various groups of its frequency resonances to be selected electronically using three switches. Therefore, seven different states are achieved, and so three, two, or one resonances are possible at the same time. By using three sickle-shaped slots in the ground plane and three pairs of p-i-n diodes that are soldered between three metal strips inside the slots and the ground plane, the antenna can support 2.4-GHz Bluetooth and/or 3.5-GHz WiMAX and/or 5.8-GHz WLAN systems. The advantage of this design is that it overcomes the problem of conventional reconfigurable antennas of serving one frequency band at a time. The antenna design, simulation, and measurement results are presented. The antenna shows similar radiation patterns with low cross-polarization levels at all its operating frequencies. The simulated and measured results are in good agreement.

Polarization Reconfigurable Slot Antenna With a Novel Compact CPW-to-Slotline Transition for WLAN Application

A polarization reconfigurable slot antenna with a novel coplanar waveguide (CPW)-to-slotline transition for wireless local area networks (WLANs) is proposed and tested. The antenna consists of a square slot, a reconfigurable CPW-to-slotline transition, and two p-i-n diodes. No extra matching structure is needed for modes transiting, which makes it much more compact than all reference designs. The -10 dB bandwidths of an antenna with an implemented bias circuit are 610 (25.4%) and 680 MHz (28.3%) for vertical and horizontal polarizations, respectively. The radiation pattern and gain of the proposed antenna are also tested, and the radiation pattern data were compared to simulation results.

A Frequency Reconfigurable CPW-Fed Slot Antenna

This paper proposed a frequency reconfigurable CPW center-fed slot antenna. Four pin-diodes are utilized to switch the length of the slot. By tuning the different pairs of diodes on or off, three resonant frequency bands can be obtained. The simulated and measured results validate this concept. This antenna architecture is interesting for wireless applications because it is easily fabricated and integrated with RF circuitry.

Dual-Band Reconfigurable Antenna With a Very Wide Tunability Range

A new technique for designing dual-band reconfigurable slot antennas is presented. Dual-frequency operation is achieved by loading a slot antenna with two lumped variable capacitors (varactors) placed in proper locations along the slot. Loading the slot antenna with lumped capacitors shifts down the resonant frequencies of the first and second resonances of the antenna. However, these frequency shifts depend not only on the values of the capacitors, but also on their locations along the slot antenna. Here, it is shown that by choosing the locations of the varactors appropriately, it is possible to obtain a dual-band antenna whose first and second resonant frequencies can be controlled individually. In other words, the frequency of either the first or the second band can be fixed, while the other one is electronically tuned. Using such a design, an electronically tunable dual-band antenna is designed and fabricated using two identical varactors having a capacitance range of 0.5-2.25 pF. The antenna is shown to have a frequency ratio (f/sub R/=f/sub 2//f/sub 1/) ranging from 1.3 to 2.67. An important feature of this antenna is its consistent radiation pattern, polarization, and polarization purity at both bands and across its entire tunable frequency range.

A Varactor-Tuned Dual-Band Slot Antenna

A new technique for designing dual-band reconfigurable slot antennas is introduced. The technique is based on loading a slot antenna with a lumped capacitor (or varactor) at a certain location along the slot. Given a fixed capacitor location along the slot, decreasing the capacitance results in increasing the first and second resonant frequencies of the slot antenna. However, the changes in the resonant frequencies are significantly different for the first and second resonances and, hence, a dual-band antenna with considerable frequency ratio tuning range can be obtained. Based on this technique, an electronically tunable dual-band antenna with a frequency ratio in the range of 1.2-1.65 is designed and fabricated using a single varactor with a capacitance range of 0.5-2.2 pF. The antenna has similar radiation patterns with low cross-polarization levels at both bands and across the entire tunable frequency range.

순차적으로 전압 인가된 RF MEMS스위치를 이용한 재구성 슬롯 안테나의 설계

In this paper, we designed a reconfigurable slot antenna using sequentially voltage-applied RF MEMS switches. In order to obtain pull-in voltage and maximum stress of the MEMS switches, the switch structures in accordance with airgap height was analyzed by ANSYS simulation A actuation voltage of MEMS switches can be determined by switch geometry and airgap height between a movable plate and a bottom plate. The designed lengths of MEMS switches were 240 , 320 , 400 , respectively and the airgap was 6. The total size of the designed slot antenna was 10 mm x 10 mm and the slot length and width were 500 and 200 , respectively. The length and size of the CPW feedline were 5 mm and 30-80-30 , respectively. and then the size of the CPW in the slot was 50-300-150 . The tuning of the resonant frequency of the proposed device is realized by varying the electrical length of the antenna, which is controlled by applying the DC bias voltages to the RF MEMS switches. The designed slot antenna has been simulated, fabricated and measured

A reconfigurable slot antenna with switchable polarization

A novel reconfigurable slot antenna architecture allowing polarization switching is presented. The antenna shape consists of a slot-ring with perturbations which are switched on and off using pin-diodes. Two antennas allowing switching either between linear and circular polarization or between two circular polarizations are demonstrated. The antenna architecture is interesting for commercial wireless applications because it is compatible with modern fabrication processes and can be realized on low cost dielectric materials.