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The report contains the experimental and theoretical results obtained in a study to further develop an electronically controllable microwave window used as a single-pole, single-throw switch. Fabrication improvement and structure optimization resulted in advancing, by more than an order of magnitude, the state of the art in high-power broad-band semiconductor microwave switches at S- and X-band frequencies. A discussion is given of the microwave operating characteristics of the window which are basic for optimizing the window design. The recombination mechanisms present in the device are discussed. An account is given of the fabrication procedures used in the practical realization of the devices. The microwave mounts used for both S- and X-band windows are described. The results of the microwave tests carried out in the fabricated windows for determining their switching characteristics are presented. (Author)

The main objective of the research study was to further develop electronically controllable S- and X-band microwave windows. Results of the calculations carried out for determining the microwave transmission properties of X-band windows are presented. These show that the windows should be 4 to 7 mils thick to achieve switching from 0.5 db to 15 db with a resistivity change from 300 ohm-cm to 1 ohm-cm. The photolithographic mask and waveguide mount which was fabricated for the implementation of the X-band windows are described. Inductive strips in the injecting line structure reduce the insertion loss to 0.3 db. The X-band measurements carried out to test the broad band and low insertion loss capabilities of the windows are presented. (Author)

The main objective of this research study is to develop an electronically controllable S-band microwave silicon window in order to overcome some of the limitations of junction-type diodes in microwave switching applications. The modifications made on our high power S-band test facility, for achieving higher accuracy in small loss measurements, are described. The results of microwave tests performed on the previously designed windows of different resistivities, are presented. Graphs are given which show the spatial distribution of the injected excess carrier density in the window structure for several values of surface recombination velocity. The allowed depths of the p+ and n+ diffused layers for an efficient performance of the window are determined. An account is given of the laboratory procedure followed for the fabrication of the p-i-n silicon window structure.

The main objective of this research study is to develop an electronically controllable S-band microwave silicon window in order to overcome some of the limitations of junction-type diodes in microwave switching applications. In this report the facilities for carrying out S-band low and high power level tests on the microwave windows are described. The advantages of mounting the silicon window in a reduced height waveguide are indicated, and the details are given of the design of a S-band microwave transformer in order to match the reduced height waveguide to the standard height waveguide used in the microwave test set up. A description is given of the way the silicon window is mounted in the reduced height waveguide. The solution to the problem of determining the distribution of excess carriers is given and the results obtained are compared with the ones obtained in a previous report.

A single, silicon element, iris limiter component was developed for X and K-band operation. Typical limiters have provided good isolation (25 db ) with small low level loss (0.5 dB) and good high power handling capability (20 KW at X-band and 10 KW at Ku-band). Numerous fabrication procedures and element structures were evaluated in order to obtain an optimal element. The use of shallow diffused contacts, a checkerboard configuration, and a thin ( 3 to 5 mils) dot-plane structure proved most desirable. Compensated GaAs elements were investigated. Multiple slit irises and filter techniques were investigated in order to achieve broader bandwidth operation. A three element filter comprised of one active limiter and two passive cavities doubled the 1 dB down bandwidth. Similar broadband performance was achieved with a double slit iris, with improved low level loss, but degraded limiting characteristics. (Author)

The primary objectives of this program are the optimization of an existing X-band microwave limiter component and the development of a similar component at Ku-band. A brief discussion is given of the microwave circuit model that has been developed to determine the effects of parameter changes on limiter component evaluation. Appropriate silicon devices for use in a simple resonant iris limiter structure have been fabricated and the microwave test results are presented and discussed. One of these new device structure, the 'checkerboard' diffused contact device, proved to be particularly attractive. This device provided small low level insertion loss along with greater limiting at given power levels than previously tested devices. (Author)