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Design and Implementation of Ka band Low Noise Amplifiers and Limiters

Mahmoudi Daryan, Parisa | 2013

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 45744 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Medi, Ali
  7. Abstract:
  8. Todays the use of microwave integrated circuits for military and commercial applications has gained much attention, especially with the advent of monolithic microwave integrated circuits, which provide the possibility of fabrication of amplifiers in large number, sufficient accuracy an affordable price.GaAs pHEMT process, because of good characteristics for noise and power in high frequencies, is a good choice for microwave and millimeter wave integrated circuits. A low noise amplifier is a key block in the receiver and, its noise figure and gain directly affects the sensitivity and dynamic range of the receiver. Hence, a low noise amplifier with low NF, high gain, good return loss, low power dissipation and suitable size is required for many systems. In addition, limiters are placedprior to LNAs in order to protect receiver chain from high input powers. Because of placing limiters as the first block in the receiver, power loss in the limiter directly increases the noise figure.Therefore, the limiter should have minimum loss. In this projecttwo low noise amplifiers in Ka frequency band designed and fabricated. The first amplifier is based on three common source stages which Derivative Superposition (DS) method is used in last stage to improve linearity. Cascode topology is deployed in the second amplifier in order to enhance gain without increasing power consumption. These methods are used for the first time in Ka frequency band. The design goals of LNAs were to have a NF less than 2 dB, gain more than 20 dB, impedance matching better than 10 dB and P1dB about -5 dBm in the input. Moreover, a passive limiter designed based on schottky diodes. Finally, to increase maximum input power range,an active limiter based on transistors designed for the first time in Ka frequency band. Maximum tolerable input powers of limiters are respectively 33 dBm and 35 dBm.Design and implementation is doneon 0.1 um pHEMT GaAs process
  9. Keywords:
  10. Pseudo High Electron Mobility Field Effect Transistor (pHEMT) ; Limiter ; Low Noise Amplifier (LNA) ; Noise Figure ; Gallium Arsenaide Technology

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