WAFER TYPE MILLIMETER WAVE RECTIFIERS 1397 



point contact spring in a standard unit. The standard and reverse- 

 polarity wafer have the same outer physical dimensions and thus they 

 may be used interchangeably in the holders as dictated by the specific 

 problems at hand. 



CONCLUDING REMARKS 



Aside from their intended use as first detectors in double detection 

 receivers, wafer units have been used for single detection measurements 

 at freauencies as high as 107 kmc. 



It is felt that the pilot production group of one hundred units is a 

 sample of sufficient size to yield representative data and to demonstrate 

 the practicability of the design. It should be pointed out that the units 

 have not been filled with protective waxes and hsive not been subjected 

 to temperature-humidity cycling tests. However, a few reference units 

 have been in use in the laboratory for over a year and have shown no 

 measurable deterioration. No attempt has been made to establish a 

 burn-out rating for the rectifier, but units have withstood available cw 

 input powers of the order of 15 milliwatts and narrow pulse discharges 

 of the order of xV ^rg without causing noticeable changes in the con- 

 version loss or noise ratio. 



ACKNOWLEDGMENTS 



The author wishes to express his gratitude to H. T. Friis and A. B. 

 Crawford for their helpful suggestions and guidance during the course 

 of this work. Extensive use has also been made of the experience and 

 techniques of R. S. Ohl. E. F. Elbert participated in the development 

 of the wafer unit, being particularly concerned with the techniques of 

 fabrication. H. W. Anderson and S. E. Reed were most helpful in solving 

 mechanical problems encountered in the production of wafer units and 

 holders. 



APPENDIX 



This section describes some calculations that were made for the pur- 

 pose of estimating the values of the various parameters involved in the 

 design of a high frequency point contact rectifier. These parameters are 

 the barrier resistance, the spreading resistance, the capacitance of the 

 barrier layer and the inductance of the contact spring. Knowing the ap- 

 proximate values of these parameters one can, by an equivalent circuit 

 analysis, arrive at a simple parallel circuit for the rectifier which may 



