Microwave (Imp Questions)

                                                                        

                                                                                                          COLLEGE  ROLL NO:………………..

DRONACHARYA GROUP OF INSTITUTIONS, G.NOIDA.

          

 SESSION- 2011-2012

Microwave Engineering (EEC 603)

ASSIGNMENT 2

1)       A signal of power 28 MW is fed into one of the collinear ports of lossless H-plane Tee. Find the power in the remaining ports when other ports are terminated by means of matched loads.

2)     In an H-plane Tee junction, 20 MW power is applied to port 3 which is perfectly matched. Find the power delivered to the load 60 Ω and 75 Ω converted to Port 1 & 2.

3)     Explain waveguide Tee in detail & find out S- Matrix of each Tee.

4)     Explain Microwave propagation in ferrites.

5)     Explain Microwave circulators. 

6)     Explain Microwave isolators.

        

ASSIGNMENT 4

1)      Explain construction & operation of TWT.

2)     Explain mode of operation of microwave BJT.

3)     Explain hybrid π-model of BJT.

4)     Explain VI charters tics of JFET & also define boundary condition .

5)     Explain small signal equivalent circuit of GaAs MESFET.

6)     A reflex Klystron operates under the following condition :  V₀= 500v ,  R_sh= 20 KΩ, n=2 ,  f_r=8    GHz ,  L= 1 mm is the spacing b/w repeller and cavity .  
      i) Value of repeller voltage
     ii) Direct current necessary to give microwave gap voltage of 200V.
    iii) Electronic efficiency .

               

ASSIGNMENT 5

        

1)       A typical n-channel GaAs MESFET has the following parameters Electron concentration  N = 8 x 10  cm , channel height  a=0.1 µm , relative dielectric constant ε_r      , Channel length  L= 14 µm , Channel width  Z=36 µm, Electron mobility  µ =     .o8 m²/V.s , Drain voltage  V _d = 5 volts , Gate voltage  V_g= -2 volts , Saturation drift velocity  V_s = 2x 10⁵   m/s       
     a)    Calculate the pinch off voltage .                               
     b)   Compute the velocity ratio     
     c)    Determine the saturation current at V_g = 0 ,               
     d) Find the Drain Current .

2)      A Two Cavity  Klystron operates under the following condition :  V₀= 900v ,  I₀= 30 mA,    d= 1 mm cavity , R_sh= 49 GΩ, n=2 ,  f=8 GHz ,  L = 4 mm . Find           
      i)   The electron velocity             
      ii) The input voltage for maximum output voltage ,                                                    
     iii) The dc transit time of electron
      iv) voltage gain in db.    

3)      Explain the Tunnel Diode.

4)     Explain the Backward Wave Oscillator.