The PN Junction

Part of the Electrical/Computer Science and Engineering Series book series (NRECSES)


The use of PN and PIN diodes to switch microwaves is a technology that is over 20 years old. [1, 2] Within that period, many engineers involved in microwave switching have observed that a small dc forward bias current of 100 m/A is sufficient to turn on a PIN diode such that it is essentially a short circuit to microwave signals with current amplitudes of tens of amperes, and that a -100 V dc reverse bias is sufficient to hold the diode in a nonconducting capacitance state even though the peak RF voltage impressed upon it may be as large as 1000 V. This operation is shown diagram-matically in Figure I-1. It would be an understatement to say that such a situation is useful as well as remarkable. But the reasons underlying it often are given too little, even inaccurate, thought. Misleadingly, this important behavior is often explained by an inertial argument — “The diode conduction mechanism cannot respond rapidly enough to follow the RF waveform; hence, its impedance state is established by the dc bias.”


Minority Carrier Forward Bias Majority Carrier Junction Potential Depletion Zone 
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  1. [1]
    Armstead, M.A.; Spencer, E.G.; and Hatcher, R.D.: “Microwave Semiconductor Switch,” Proceedings of the IRE, Vol. 44, p. 1875, December 1956.Google Scholar
  2. [2]
    Garver, R.V.; Spencer, E.G.; and Harper, M A.: “Microwave Semiconductor Switching Techniques,” IRE Transactions on Microwave Theory and Techniques, Vol. MTT- 6, pp. 378–383, October 1958.CrossRefGoogle Scholar
  3. [3]
    Phillips, Alvin, B.: Transistor Engineering (Chapters 2–6), McGraw-Hill, Inc., New York, 1962.Google Scholar
  4. [4]
    Watson, H.A., (ed.): Microwave Semiconductor Devices and Their Circuit Applications (Chapters 2–7), McGraw-Hill, Inc., New York, 1969.Google Scholar
  5. [5]
    McKay, K.G.: “Avalanche Breakdown in Silicon,” Physical Review, Vol. 94, pp. 877–884, May 1954.CrossRefGoogle Scholar

Copyright information

© Van Nostrand Reinhold Company 1982

Authors and Affiliations

  1. 1.Microwave Associates, Inc.BurlingtonUSA

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