A PIN diode can be used in either a series or a shunt configuration to form a __________
1.Single pole single throw switch
2.Single pole double throw switch
3.Amplifier
4.Oscillator
Any semiconductor diode has a junction capacitance varying with reverse bias. If such a diode has microwave characteristics, it is called:
1. IMPATT diode
2.TRAPITT diode
3.SKOTTKY diode
4.None of the mentioned
As the degree of non-linearity of a transistor or a diode increases, the power gain of the device:
1.Increases
2.Decreases
3.Remains a constant
4.None of the mentioned
For a shunt configuration switch, the diode impedance is 40 Ω and the terminated line characteristic impedance is 50 Ω. Then the insertion loss of the switch is:
1.2.2 dB
2.4.2 dB
3.8.4 dB
4.3.6 dB
GaAs is used in the fabrication of GUNN diodes because:
1.GaAs is cost effective
2.It less temperature sensitive
3.it has low conduction band electrons
4.less forbidden energy gap
Gain of a parametric amplifier in terms of the frequencies involved in their operation is:
1.(fP – fS)/fS
2. fS/ (fP – fS)
3. fP/fS
4.None of the mentioned
If the third order intercept point of a receiver is 35 dBm and the total noise in the receiver is -47.4 dBm signals to noise ratio is 10, then the spurious free dynamic range is:
1. 50.9 dB
2. 44.9 dB
3. 34.9 dB
4.67 dB
In a coherent cascade network, if the third order intercept point of an amplifier is 158 mW and the third order intercept point of a mixer is 5 mW, with an insertion loss of 6 dB, then the third order intercept point of the coherent cascade is:
1.2 mW
2.4 mW
3. 4.4 mW
4.5 mW
In a non coherent cascade network, if the third order intercept point of an amplifier is 158 mW and the third order intercept point of a mixer is 5 mW, with an insertion loss of 6 dB, then the third order intercept point of the coherent cascade is:
1. 3 mW
2.4.9 mW
3.5.2 mW
4. 2 mW
In the plot of the magnitude of electric field around the periphery of the junction circulator, the curve has:
1.Three peaks
2.Two peaks
3.Four peaks
4.None of the mentioned
In the series configuration of a PIN diode switch, the terminated load impedance was found to be 50 Ω and the diode impedance was 60
1.4 dB
2.2 dB
3.3.6 dB
4.4.8 dB
The expression for linear dynamic range is given by:
1.OP1 dB- No
2.OP1 dB/ No
3.OP1 dB+No
4.None of the mentioned
The magnetic properties of a material are due to the existence of ___________
1. Electrons in atoms
2.Electric dipole moment
3.Magnetic dipole moment
4.None of the mentioned
The output response of a non-linear circuit is given by the expression:
1.V0=a0+a1Vi1+a2Vi2+a3Vi3…
2.0=a0+a1Vi1
3.V0=a2Vi2+a3Vi3
4.V0=a0
The resistance of the PIN diode with positive bias voltage:
1.Increases
2.Decreases
3.Remains constant
4.Insufficient data
The width of depletion region of a varactor diode ________with increase in reverse bias voltage.
1.IncreasesIncreases
2.Decreases
3.Remains constant
4.None of the mentioned
Varactor diode is a semiconductor diode in which the _________ can be varied as a function of reverse voltage of the diode.
1.Junction resistance
2.Junction capacitance
3.Junction impedance
4.None of the mentioned
Varactors made of ______ have higher frequency range of operation compared to silicon fabricated varactor diodes.
1.Germanium
2.GaAs
3.GaN
4.None of the mentioned
Varactors made of ______ have higher frequency range of operation compared to silicon fabricated varactor diodes.
1.Germanium
2.GaAs
3.GaN
4.None of the mentioned
Varactors made of ______ have higher frequency range of operation compared to silicon fabricated varactor diodes.
1.Germanium
2.GaAs
3.GaN
4.None of the mentioned
When the electric field applied to GaAs specimen is less than the threshold electric field, the current in the material:
1.increases linearly
2.decreases linearly
3.increases exponentially
4.decreases exponentially
. In a non-linear device, for a single input frequency the output will consist of:
1.Single frequency component
2.Harmonics of the input frequency
3.Constant gain
4.None of the mentioned
A PIN diode consists of ______number of semiconductor layers.
1.Three
2.Two
3.Four
4.one
A receiver has a noise figure of 7 dB, gain of 40 dB, noise temperature is 290 K. then the noise power at the receiver is:
1.47. 4 dBm
2. -47.4 dBm
3.23 dBm
4. -23 dBm
Active devices like diodes and transistors become non-linear at high power levels due to:
1.Instability of transistor
2.Thermal noise
3. Gain compression
4.None of the mentioned
After demagnetization of a magnetic material, the residual magnetization retained in the magnetic material is called:
1.Remanence
2.Residue
3.Retardation
4.None of the mentioned
An amplifier has a noise equivalent temperature of 170 K. If the amplifier is used with a source having an equivalent noise temperature of TS=450 K, the output noise power of the amplifier is:
1. -50 dBm
2.-60 dBm
3.-60.7 dBm
4.-55 dBm
An X- band amplifier has a gain of 20 dB and a gain of 1GHz bandwidth. Noise figure of the amplifier is -62 dBm at 290 K and -64.7 dBm at 77 K. then the Y factor of the amplifier is :
1.3 dB
2.6.4 dB
3.2.7 dB
4.5.6 dB
Equivalent noise temperature associated with an arbitrary white noise source is:
1.N0/GKB
2.N0
3. N0/ kB
4.None of the mentioned
Ferrite isolators are ____ port microwave devices.
1.Two
2.Three
3.Four
4.None of the mentioned
For a receiver, 1 dB compression point is 25 dBm and the noise power at the receiver output is -47.4 dBm, the linear dynamic range is:
1.70 dB
2.72.4 dB
3.68 dB
4.85 dB
Forward attenuation provided by a resonance ferrite isolator is:
1.Zero
2.Low
3.High
4.None of the mentioned
Gyrator is a device that produces a phase shift of ____ between the input and output.
1.90⁰
2.180⁰
3.45⁰
4.None of the mentioned
If a ferrite slab provides a phase shift of 48⁰/ cm, then the length of the ferrite slab required to produce a phase shift of 180⁰ is:
1.4 cm
2.3.75 cm
3.4.5 cm
4.3.5 cm
If a ferrite slab provides a phase shift of 48⁰/ cm, then the length of the ferrite slab required to produce a phase shift of 90⁰ is:
1.2.44 cm
2.1.88 cm
3.4.5 cm
4.3.5 cm
In a stripline junction circulator, the ferrite material is present in the form of a:
1.Slab
2.Ferrite disk
3.Ferrite material is not used in a microstrip circulator
4.Ferrite cubes
In the scattering matrix representation of a non-ideal circulator, the diagonal elements of the matrix are:
1.Zero
2.One
3.Reflection coefficient Г
4.None of the mentioned
Parametric amplifier is a ________ amplifier.
1.Low noise
2.High gain
3.Low gain
4.High noise
Passive intermodulation is significant only when:
1.The input signal levels are low
2. Input signal levels are high
3.Input signal is sinusoidal
4.Input signal is exponential
Phase shifters are used in _______ where the antenna beam can be steered in space by electronically controlled phase shifters.
1.Phased array antennas
2.Dipole array antennas
3.Slot antennas
4.Patch antennas
Practically, opposite circulatory in a ferrite circulator can be obtained by:
1.Changing the order of port operation
2.Impedance matching the input ports
3.Changing the polarity of the magnetic bias field
4.None of the mentioned
Silicon and germanium are called ___________ semiconductors.
1. direct gap
2.indirect gap
3.band gap
4. indirect band gap
The attenuation of a ________ is very large near the gyro magnetic resonance of the ferrite.
1.Linearly polarized wave
2.Circularly polarized wave
3.Left polarized wave
4.Right polarized wave
The cutoff frequency for operation of a varactor diode at a specific bias is given by:
1.1/2πRSCjv
2. 1/2πCSRjv
3.1/2π√LC
4.None of the mentioned
The electric field distribution of the forward and reverse waves in a ferrite slab-loaded waveguide is quite different. This property is used in:
1.Field displacement resonator
2.Resonance isolator
3.Waveguide isolator
4.None of the mentioned
The isolators constructed using ferrite materials must operate at:
1.Gyro magnetic resonance
2.Magnetic resonance
3.Isolator resonance
4.None of the mentioned
The junction resistance and capacitance of the intrinsic region in a PIN diode are connected______ in the equivalent circuit of PIN diode.
1.Series
2.Parallel
3.Connected across package capacitance
4.None of the mentioned
The length of a ferrite slab required operating with a minimum forward insertion loss and 30 dB reverse attenuation and the reverse attenuation at this point is:
1.3 cm
2.2.4 cm
3.4 cm
4.3.6 cm
The material out of which PIN diode is made is:
1.Silicon
2.Germanium
3.GaAs
4.None of the mentioned
The matrix of an ideal isolator is not ______
1.Unitary
2.Symmetric
3.Lossless
4.None of the mentioned
The matrix of an ideal isolator is not ______
1.Unitary
2.Symmetric
3.Lossless
4.None of the mentioned
The noise power associated with a two port network modeled as thevinin equivalent is:
1.kTB
2.k/TB
3.TB/ K
4.None of the mentioned
The operating point of a permanent magnet is in the:
1.First quadrant
2.Second quadrant
3.Third quadrant
4.Fourth quadrant
The relation between an intercept points referenced at the input versus the output is given by the relation:
1.OIP3=G (IIP3)
2.(IIP3) = G (OIP3)
3.OIP3=G (IIP3)2
4.None of the mentioned
The scattering matrix of a gyrator is:
1.Symmetric
2.Skew symmetric
3.Identity matrix
4.Null matrix
The total number of ones in the scattering matrix of an ideal circulator is:
1.4
2.3
3.5
4.2
The type of noise caused by vibration of bound charges is called:
1.Thermal noise
2.Shot noise
3.Flicker noise
4.None of the mentioned
The Y factor of an amplifier obtained by measuring the noise figure at the temperatures 77 K and 290 K is 2.7 db. Then the equivalent noise temperature of the amplifier is:
1.100 K
2.150 K
3.170 K
4.None of the mentioned
The ________property of devices like diodes and transistors is responsible for their usage in amplifiers and frequency convertors.
1.Symmetry
2.Non linearity
3.Linearity
4.None of the mentioned
This is not an example of anisotropic material:
1.Yttrium aluminum garnet
2.Aluminum
3.Cobalt
4.Silicon
Under ideal conditions, when a PIN diode is used as a switch, the switch must have _______ insertion loss in the ON state.
1.Maximum
2.Zero
3.Average
4.Insertion loss cannot be defined for a switch
When PIN diode is used as a switch, the expression for insertion loss of the switch is given by:
1.10 log (Po/PL)
2.10 log (PL/P0)
3.10 log (PL. Pₒ)
4.None of the mentioned
When the input frequency consists of more than one closely spaced frequency, it results in:
1.Intermodal distortion
2.Gain compression
3.Signal fading
4.Signal attenuation
_______ is a three-port microwave device that can be lossless and matched at all spots.
1.Hybrid junction
2.Magic Tee
3.Circulator
4.Isolator
________ is defined as the operating range for which a component or system has desirable characteristics.
1.Static range
2.Dynamic range
3.Characteristic gain
4.None of the mentioned
________ noise is caused by random motion of charges in ionized gas.
1.Plasma noise
2.Quantum noise
3.Thermal noise
4.Flicker noise
________ noise occurs due to the random fluctuation of charge in an electron tube.
1. Flicker noise
2.Shot noise
3.Thermal noise
4.White noise
__________ is a measure of the relative contributions of the orbital moment and the spin moment to the total magnetic moment.
1.Lande’s factor
2.Gibbs factor
3.Newton’s ratio
4.None of the mentioned
__________ is a measure of the relative contributions of the orbital moment and the spin moment to the total magnetic moment.
1.Lande’s factor
2.Gibbs factor
3.Newton’s ratio
4.None of the mentioned
___________ is an amplifier constructed using a device whose reactance is varied to produce amplification.
1.Travelling wave tube
2.Parametric amplifier
3.Common emitter
4.Klystron amplifier