A Medium Power Solid State Amplifier for V-Band
A solid state amplifier for the 54 to 58 GHz band is described. The amplifier uses two layer InP Gunn devices. Three stages of amplification provide an output power of 100 mW at a gain of 15 dB. The small signal gain is 30 dB; the noise figure is in the 15.5 to 16.5 dB range. The design of a broadband low-loss V-band circulator, which was used in the amplifier, is also described.
Chapter 10 – Transferred Electron Devices
Publisher Summary 
This chapter begins with a discussion on transferred-electron diodes, or Gunn diodes. Gunn diodes are not true diodes because a “diode” is usually defined as a device having an asymmetrical current-voltage characteristic. As Gunn diodes possess a current-voltage characteristic similar to that of resistors, the terms “transferred-electron device” or “Gunn device” are more formerly used. The chapter reviews the Gunn device mechanism, fabrication technology, and applications. The chapter also provides an overview of negative differential mobility, device modeling, Gunn device design, and its fabrication. It explains the construction of various forms of Gunn oscillators and circuits. Gunn amplifiers and noise characteristics are also explored in the chapter. In the concluding part, the chapter describes the power-combining techniques of Gunn devices. Gunn diode oscillators have proved to be a reliable microwave and millimeter-wave solid-state frequency source. The GaAs Gunn diodes are used extensively in microwave and millimeter-wave systems from 3 to 120 GHz.
Laminar heat or mass transfer in rectangular channels and in cylindrical tubes for fully developed flow: comparison of solutions obtained for various boundary conditions
Abstract A comparison is made of results obtained with various boundary conditions at the wall of the channels. By comparing blood Sherwood numbers for finite wall resistance with those for constant concentration boundary condition only a small variation is found for various points along the blood channel.