A new room temperature wet chemical digital etching technique for GaAs is presented which uses hydrogen peroxide and an acid in a two‐step etching process to remove GaAs in approximately 15 Å increments. In the first step, GaAs is oxidized by 30% hydrogen peroxide to form an oxide layer that is diffusion limited to a thickness of 14 to 17 Å for time periods from 15 to 120 s. The second step removes this oxide layer with an acid that does not attack unoxidized GaAs. These steps are repeated in succession until the desired etch depth is obtained. Experimental results are presented for this digital etching technique demonstrating the etch rate and process invariability with respect to hydrogen peroxide and acid exposure times.

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This article experimentally studies the application of vanadium dioxide (VO 2 ) thin film for tunable inductor design. VO 2 's temperature-dependent conductivity is used for implementing a tunable inductor using VO 2 as the control material. Two different configurations of inductors are designed. One design uses a short VO 2 bar as a circuit switch and the other uses VO 2 to replace the full spiral coil inductor. The frequency range in the experiments is 0.3-2 GHz. Experimental results show a 32% tuning range (1-0.68 nH) through applied temperature variation (25-1008C) in the devices. These results are matched by a working circuit p model. ABSTRACT:In this work, a dual bands omnidirectional monopole antenna is proposed. A planer Y-shaped patch is loaded on the top of the surface and a slot is loaded on the ground plane to obtained broadband. Rogers RT/duroid5880(tm) substrate is used with dielectric constant 2.2 and loss tangent 0.0009. The results of the proposed antenna for the variation of width and length of the ground plane are investigated. Two licensed free frequency bands at 2.4 GHz and 5.8 GHz are obtained for WiFi and Bluetooth application. The measured frequency bands of 2.3-2.52 GHz at 2.4 GHz and 4.22-10.30 GHz with two resonant frequencies at 4.96 and 8.36 GHz are obtained. The peak antenna gain of 4.6 dBi at 2.4 GHz is achieved. Simulation has been done using MOM base Ansoft designer software.

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