Category: Microwave Engineering Objective Questions

250+ TOP MCQs on PIN Diodes and Answers

Microwave Engineering Multiple Choice Questions on “PIN Diodes”.

1. A PIN diode consists of ______number of semiconductor layers.
A. Three
B. Two
C. Four
D. One
Answer: a
Clarification: PIN diode is a p-type, intrinsic, n-type diode consisting of narrow layer of p-type semiconductor and a narrow layer of n-type semiconductor material, with a thicker region of intrinsic or very lightly n doped semiconductor sandwiched between them.

2. The material out of which PIN diode is made is:
A. Silicon
B. Germanium
C. GaAs
D. None of the mentioned
Answer: A
Clarification: Silicon is the semiconductor normally used because of its power handling capability and it offers high resistivity for the intrinsic region. But depending on the application, these days GaAs is also used in fabricating PIN diodes.

3. The behavior of a PIN diode is entirely different from normal diodes at all frequency of operation.
A. True
B. False
Answer: B
Clarification: PIN diode acts as a ordinary diode at frequencies up to about 100MHz. at high frequencies it stops to rectify and then acts as a variable resistance.

4. The junction resistance and capacitance of the intrinsic region in a PIN diode are connected______ in the equivalent circuit of PIN diode.
A. Series
B. Parallel
C. Connected across package capacitance
D. None of the mentioned
Answer: B
Clarification: The junction capacitance Cj and junction resistance Rj of a PIN diode are connected in parallel in the equivalent circuit of a PIN diode. The package resistance and package capacitance are connected in series to these junction parameters.

5. The resistance of the PIN diode with positive bias voltage:
A. Increases
B. Decreases
C. Remains constant
D. Insufficient data
Answer: B
Clarification: When the bias is varied on the PIN diode, its microwave resistance RJ changes from a typical value of 6 KΩ under negative bias to perhaps 5 Ω under forward bias. Thus if the diode is mounted on a 50Ω coaxial line, it will not significantly load this line.

6. A PIN diode can be used in either a series or a shunt configuration to form a __________
A. Single pole single throw switch
B. Single pole double throw switch
C. Amplifier
D. Oscillator
Answer: A
Clarification: A PIN diode can be used in either a series or a shunt configuration to form a single pole single throw switch. In the series configuration, the switch is on when the diode is forward biased and off when the diode is reverse biased.

7. The working principle of series and shunt configuration single pole single throw switch is the same.
A. True
B. False
Answer: B
Clarification: In the series configuration, the switch is on when the diode is forward biased and off when the diode is reverse biased. In the shunt configuration, forward biasing the diode cuts-off the transmission while reverse biasing the diode ensures transmission from input to output.

8. Under ideal conditions, when a PIN diode is used as a switch, the switch must have _______ insertion loss in the ON state.
A. Maximum
B. Zero
C. Average
D. Insertion loss cannot be defined for a switch
Answer: B
Clarification: Ideally, when PIN diode is used as switch, the switch should have zero insertion loss in the ON state and infinite attenuation in the OFF state. These are ideal conditions. But practically a good operating switch must have low insertion loss.

9. When PIN diode is used as a switch, the expression for insertion loss of the switch is given by:
A. 10 log (Po/PL)
B. 10 log (PL/P0)
C. 10 log (PL. Pₒ)
D. None of the mentioned
Answer: A
Clarification: Insertion loss of a switch is defined as the ratio of incident power applied to the load when switch is absent to the actual power delivered to the load.

10. 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:
A. 2.2 dB
B. 4.2 dB
C. 8.4 dB
D. 3.6 dB
Answer: B
Clarification: Insertion loss of a shunt configuration switch is given by 20 log (2ZD+Z0/2ZD). Substituting the given values in the above expression, the insertion loss of the shunt configuration switch is 4.2 dB.

11. 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 Ω. Then the insertion loss of the switch is:
A. 4 dB
B. 2 dB
C. 3.6 dB
D. 4.8 dB
Answer: A
Clarification: Insertion loss of a shunt configuration switch is given by 20 log (2ZD+Z0/2ZD). Substituting the given values in the above equation, the insertion loss is 4 dB.

12. The number of PIN diodes used in SPST switch and SPDT switch are the same.
A. True
B. False
Answer: B
Clarification: The number of PIN diodes in SPST switch is one, while the number of PIN diodes used in single pole double throw switch is two.


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250+ TOP MCQs on Power Amplifiers and Answers

Microwave Engineering Multiple Choice Questions on “Power Amplifiers”.

1. _______________ are used in the final stages of radar and radio transmitters to increase the radiated power level.
A. Power amplifiers
B. Oscillators
C. Transistors
D. Attenuators

Answer: A
Clarification: Power amplifiers are used in the final stages of radar and radio transmitters to increase the radiated power level. Output of power amplifiers are in the range of 100-500 mW.

2. Important factors to be considered for power amplifier design are:
A. Efficiency
B. Gain
C. Thermal effect
D. All of the mentioned

Answer: D
Clarification: As per the application requirement and considering various aspects of an amplifier like efficiency, gain, thermal efficiency and inter modulation distortion, amplifiers need to be designed.

3. Amplifier efficiency is the ratio of RF output power to DC input power. This parameter determines the performance of an amplifier.
A. True
B. False

Answer: A
Clarification: Power amplifier is the primary consumer of DC power in most hand-held wireless devices, so amplifier efficiency is an important consideration. Amplifier efficiency is the ratio of RF output power to DC input power.

4. Gain of power amplifiers __________ with increase in operating frequency.
A. Increases
B. Decreases
C. Increases exponentially
D. Decreases exponentially

Answer: B
Clarification: Silicon bipolar junction transistor amplifiers in the cellular telephone band of 800-900 MHz band have power added efficiencies of about 80%. But this efficiency drops quickly with increase in the operating frequency.

5. ___________ amplifiers are linear circuits, where the transistor is biased to conduct over the entire range of the input signal cycle.
A. Class A amplifiers
B. Class B amplifiers
C. Class C amplifiers
D. None of the mentioned

Answer: A
Clarification: Class A amplifiers are linear circuits, where the transistor is biased to conduct over the entire range of the input signal cycle. Because of this, class A amplifiers theoretically have a maximum efficiency of 50%.

6. A class B amplifier consists of _______ transistors in order to conduct the input signal over the entire cycle.
A. 1
B. 2
C. 4
D. 6

Answer: B
Clarification: Class B amplifier is biased to conduct only during one-half of the input signal cycle. 2 complementary transistors are operated in a class B push pull amplifier to provide amplification over the entire cycle.

7. Power amplifiers in the increasing order of efficiency is:
A. Class A, B, C
B. Class C, A, B
C. Class B, A, C
D. Efficiency of all the 3 amplifiers is the same

Answer: A
Clarification: Class A amplifiers have an efficiency of about 50%. Class B amplifiers have an efficiency of about 78%, class C amplifiers can achieve efficiencies up to 100%. In the increasing order of efficiency, C > B> A.

8. Behavior of a transistor in power amplifiers is unpredictable at all input signal levels.
A. True
B. False

Answer: B
Clarification: A transistor behaves linearly for signal powers below 1dB compression point and so, the small –signal scattering parameters should not depend either on the input power level or the output termination impedance.

9. If the output power of an amplifier is 10 V, and the input power supplied to the amplifier is 0.229 V given that the DC voltage used is 38.5 V, efficiency of the power amplifier is:
A. 25%
B. 50%
C. 75%
D. 35%

Answer: A
Clarification: Efficiency of a power amplifier is (Pout- Pin)/ PDc Substituting the given values in the above expression, efficiency of the power amplifier is 25%.

10. If a power amplifier has an output power of 10 W, and an amplifier gain of 16.4 dB, then the input drive power is:
A. 400 mW
B. 225 mW
C. 229 mW
D. 240 mW

Answer: C
Clarification: Input drive power required to get an output of 10 W is Pout (dBm)- G (dB.. G is the gain of the amplifier. Substituting the given values in the above equation, 229 mW.

250+ TOP MCQs on Antenna Basics-2 and Answers

Microwave Engineering Questions and Answers for Entrance exams on “Antenna Basics-2”.

1. As the beam area of an antenna decreases, the directivity of the antenna:
A. Increases
B. Decreases
C. Remains unchanged
D. Depends on the type of the antenna
Answer: A
Clarification: Beam area of an antenna and the directivity of the antenna are inversely proportional. As the beam area is reduced, the directivity increases, meaning smaller the radiating area of the transmitting antenna, more directed is the emitted energy.

2. If an antenna radiates over half a sphere, directivity of the antenna is:
A. Two
B. Four
C. Three
D. One
Answer: A
Clarification: Since the antenna radiates over half the sphere, beam area of the antenna is 2π, directivity of the antenna is given by 4π/ beam area. Substituting for beam area, the directivity of the antenna is two.

3. The half power beam width of an antenna in both θ and φ are 400 each. Then the gain of the antenna is:
A. 23
B. 25
C. 14
D. 27
Answer: B
Clarification: Approximate gain of an antenna is given by the expression 40000/ (HPBW) 2. Substituting the given values in the above expression, the gain of the antenna is 25. In dB scale the gain of the antenna is 14 dB.

4. The number N of radio transmitters or point sources of radiation distributed uniformly over the sky which an antenna can resolve is given by:
A. 4π/ ΩA
B. 2π/ ΩA
C. π/ ΩA
D. None of the mentioned
Answer: A
Clarification: Resolution may be defined as equal to half the beam width between first nulls. In the above expression the resolution N is given as 4π/ ΩA.. Here ΩA is the beam area.

5. Ideally, the number of point sources an antenna can resolve is numerically equal to:
A. Gain of the antenna
B. Directivity
C. Beam efficiency
D. Beam area
Answer: B
Clarification: The number of point source an antenna can resolve is given by 4π/ ΩA Directivity of an antenna is mathematically given by the relation 4π/ ΩA . Numerically resolution and directivity are equal.

6. Effective aperture is a parameter of the antenna that gives the physical aperture of the antenna.
A. True
B. False
Answer: B
Clarification: Effective aperture defines the amount of the total aperture of the antenna that is utilized for radiation of energy. Higher the effective aperture of an antenna, more is the aperture efficiency.

7. Effective aperture in terms of beam area and operating wavelength is given by the relation:
A. λ2/ ΩA
B. ΩA / λ2
C. λ2× ΩA
D. No such relationship exists
Answer: A
Clarification: Effective aperture is given as λ2/ ΩA. Here ΩA is the beam area. If the beam area is specified in terms of the operating wavelength λ, then effective are of the antenna can be made operating wavelength independent.

8.________ of an antenna is defined as the ratio of the induced voltage to the incident electric field.
A. Effective height
B. Gain
C. Directivity
D. Loss
Answer: A
Clarification: At the receiving end, effective height of an antenna is defined as the ratio of the induced voltage to the incident electric field. Otherwise, if the effective length of the receiving antenna is known and if the induced voltage is measured, then the field strength can be determined.

9. The directivity of an antenna in terms of the aperture efficiency and operating wavelength is given by:
A. 4πAe/λ2
B. 2πAe/λ2
C. πAe/λ2
D. None of the mentioned
Answer: A
Clarification: The directivity of an antenna in terms of aperture efficiency is given by 4πAe/λ2. Here Ae is the aperture efficiency. λ is the operating frequency. With an increase in the effective aperture area of an antenna, directivity of the antenna can be increased making the radiated beam narrower.

10. A radio link has 15 W transmitter connected to an antenna of 2.5 m2 effective aperture at 5 GHz. The receiving antenna has an effective aperture of 0.5 m2 and is located at a 15 Km line of sight distance from transmitting antenna. Assuming lossless, matched antennas, the power delivered to the receiver is:
A. 20 µW
B. 15 µm
C. 23 µm
D. 25 µm
Answer: C
Clarification: The power delivered to the receiving antenna is Pt (A1 A2/ r2λ2). Substituting the given values in the above equation, the power at the receiver is 23 µm.


Microwave Engineering for Entrance exams,

250+ TOP MCQs on Terminated Lossless Transmission Lines – 1 and Answers

Microwave Engineering Multiple Choice Questions on “Terminated Lossless Transmission Lines – 1”.

1. When a lossless line is terminated with an arbitrary load impedance ZL, then it :
A. causes wave reflection on transmission lines
B. transmits the entire supplied power
C. causes loss in transmission line
D. none of the mentioned
Answer: A
Clarification: When a line is terminated with a impedance other the characteristic impedance of the transmission line, It results in reflection of waves from the load end of the transmission line hence resulting in wave reflection in the transmission line.

2. We say a transmission line is matched when:
A. ZL=Z0
B. ZL=√Z0
C. ZL=Z0/2
D. ZL=2Z0
Answer: A
Clarification: We say a line is matched only when the characteristic impedance of the transmission line is equal to the terminating load impedance. Hence condition for a line to be matched is ZL=Z0.

3. Voltage reflection coefficient can be defined as:
A. ratio of amplitude of reflected voltage wave to the transmitted voltage wave
B. ratio of amplitude of reflected voltage to the incident voltage wave
C. ratio of load impedance to the characteristic impedance of the transmission line
D. none of the mentioned
Answer: B
Clarification: From transmission line theory, reflection co-efficient of a transmission line is defined as the ratio of amplitude of reflected voltage to the incident voltage wave.

4. Expression for a voltage reflection co-efficient in terms of load impedance and characteristics impedance is:
A. (ZL– Z0)/(ZL+ Z0)
B. (ZL+ Z0)/(ZL– Z0)
C. ZL. Z0/( ZL+ Z0)( ZL-Z0)
D. (ZL+ Z0)( ZL-Z0)/ ZL. Z0
Answer: A
Clarification: The amplitude of the reflected voltage wave at the load end is equal to the difference between the load and the characteristic impedance, incident voltage is proportional to the sum of the load and characteristic impedance.

5. If a transmission line of a characteristics impedance 50 Ω is terminated with a load impedance of 100 Ω, then the reflection co efficient is:
A. 0.3334
B. 0.6667
C. 1.6
D. 1.333
Answer: A
Clarification: Expression for reflection co-efficient of a transmission line is (ZL– Z0)/(ZL+ Z0) .substituting the given values of load and characteristic impedance, we get reflection co-efficient equal to 0.3334.

6. Return loss for a transmission line in terms of its reflection co efficient is given by:
A. -20logl┌l in dB where ┌ is the reflection coefficient.
B. -10logl┌l in dB where ┌ is the reflection coefficient
C. -10log (1/l┌l) in dB where ┌ is the reflection coefficient
D. -20log (1/l┌l) in dB where ┌ is the reflection coefficient
Answer: A
Clarification: Return loss signifies the amount of energy reflected back from the load which is proportional to the reflection co-efficient of the line. Return loss in dB is given by the logarithm of the reflection co-efficient.

7. If the reflection coefficient for transmission line is 0.24, then the return lossin dB is:
A. 12.39dB
B. 15dB
C. -12.39dB
D. -15.2dB
Answer: A
Clarification: The return loss of a transmission line, given the reflection co-efficient is -20logl┌l in dB where ┌ is the reflection co-efficient. Substituting for reflection co-efficient in the above equation, return loss is 12.39dB.

8. Expression for VSWR in terms of reflection co-efficient is:
A. (1+│┌│)/(1-│┌│)
B. (1-│┌│)/(1+│┌│)
C. 1/│┌│
D. 1/1+│┌│
Answer: A
Clarification: VSWR is the ratio of maximum amplitude of the standing wave formed to the minimum amplitude of the standing wave, when these voltages are expressed in terms of reflection co-efficient, we get the expression(1+│┌│)/(1-│┌│).

9. If the reflection co-efficient for a transmission line is 0.3, then the VSWR is:
A. 0.5384
B. 1.8571
C. 0.4567
D. 3.6732
Answer: B
Clarification: VSWR (voltage standing wave ratio) in terms of reflection co-efficient is given by (1+│┌│)/(1-│┌│).substituting ┌=0.3 in this equation we get, VSWR=1.8571.

10. If a transmission line of characteristic impedance 50 Ω is terminated with a load impedance of 150 Ω, then VSWR is:
A. 0.75
B. 0.5
C. 2
D. none of the mentioned
Answer: B
Clarification: VSWR (voltage standing wave ratio) in terms of load and characteristic impedance is given by ZL– Z0 /ZL+ Z0. Substituting for ZL and Z0 in the above equation, VSWR is 0.5.


all areas of Microwave Engineering,

250+ TOP MCQs on Transmission Matrix(ABCD. and Answers

Microwave Engineering Multiple Choice Questions on “Transmission Matrix(ABCD.”.

1. ABCD matrix is used:
A. When there is two or more port networks in the cascade
B. To represent a 2 port network
C. To represent a 2 port network
D. To represent the impedance of a microwave network
Answer: A
Clarification: The Z, Y, and S parameter representation can be used to characterize a microwave network with an arbitrary number of ports. But most microwave networks consist of cascade of two or more two port networks. In this case it is convenient to use ABCD matrix for network representations.

2. The voltage equation for a 2 port network that can be represented as a matrix is:
A. V1=AV2 + BI2
B. V1=CV2 + DI2
C. V1=BV2 +AI2
D. V1=DV2+CI2
Answer: A
Clarification: In the equation, V1 is the voltage measured at port 1 and V2 is the voltage measured at port 2 and I2 is the current measured at the second port. A and B are the network constants.

3. ABCD matrix of the cascade connection of 2 networks is equal to:
A. Product of ABCD matrices representing the individual two ports
B. Sum of the ABCD matrices representing the individual two ports
C. Difference of the ABCD matrices representing the individual two ports
D. Sum of transpose of ABCD matrices representing the individual two ports
Answer: A
Clarification: When two networks are connected in cascade, each of the two networks are represented as a 2×2 square matrix. Then to obtain the equivalent matrix of the cascade, the product of the ABCD matrices of each stage is taken.

4. For simple impedance Z, the ABCD parameters are:
A. A=1, Z=B, C=0, D=1
B. A=0, B=1, C=1, D=0
C. A=Z, B=1, C=1, D=0
D. A=1, B=0, C=Z, D=1
Answer: A
Clarification: If simple impedance or an equivalent impedance of a network is represented as a ABCD matrix, writing the equations in terms of voltage and current and setting each variable to zero, the four constants are obtained. For an impedance Z, the constants are A=1, Z=B, C=0, D=1.

5. For a simple admittance Y, the ABCD parameters are:
A. A=1, B=0, C=Y, D=1
B. A=Z, B=1, C=1, D=0
C. A=1, B=0, C=Z, D=1
D. A=1, Y=B, C=0, D=1
Answer: A
Clarification: If simple admittance or an equivalent admittance of a network is represented as a ABCD matrix, writing the equations in terms of voltage and current and setting each variable to zero, the four constants are obtained. For an admittance Y, the constants are A=1, Z=B, C=0, D=1.

6. C parameter for a transmission line of characteristic impedance Zₒ, phase constant β and length ‘l’ is:
A. j Yₒ Sin βl
B. j Zₒ Sin βl
C. j Zₒ tan βl
D. j Yₒ tan βl
Answer: A
Clarification: If a transmission line is represented as two port network, constants can be derived in terms of the A, B, C, D constants for the network. But setting each electrical parameter to zero, this constant is found. By doing so, the C parameter of transmission line is j Yₒ Sin βl.

7. For a 2 port network if Z₁₁=1.5 and Z₁₂=1.2, A parameter for the same 2 port network is:
A. 1.5
B. 1.25
C. 0.75
D. 1.75
Answer: B
Clarification: A parameter for the two port network is the ratio of the impedance Z11 and the impedance Z12. Substituting in this equation,’ A’ parameter of the network is 1.25.

8. For a 2 port network, if the admittance parameter Y₁₂=0.4, then B among the ABCD, parameters for the 2 port network is:
A. 2.5
B. 4.5
C. 5
D. 6
Answer: A
Clarification: For a two port network, B parameter is defined as the reciprocal of the admittance Y12. Taking the reciprocal of the given value, the B parameter of the network is 2.5.

9. If D=1.6 and B=2.8 for a 2 port network, then Y₁₁=?
A. 0.5714
B. 0.987
C. 0.786
D. 1.75
Answer: A
Clarification: The admittance Y11 of the network is defined as the ratio of B parameter to the D parameter of the network. Taking the ratio of the given values, admittance Y11 is 0.5714.

10. If A=2.8 and B=1.4 for a 2 port network then Z₁₁=?
A. 0.5
B. 2
C. 4.2
D. 2.7
Answer: B
Clarification: Z11 parameter of a two port network is the ratio of the A parameter of the network to the B parameter of the network. Taking the ratio of the given values, Z11 is 2.


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250+ TOP MCQs on Properties of Dividers and Couplers and Answers

Microwave Engineering Multiple Choice Questions on “Properties of Dividers and Couplers”.

1. Power dividers and couplers are ______ microwave components used for power division or power combining.
A. Passive
B. Active
C. Linear
D. Non linear
Answer: A
Clarification: When a given input power is to be divided equally at microwave frequencies, power dividers are used. Since couplers and dividers do not store any energy they are called passive microwave components.

2. T- junction is an example for:
A. 2 port network
B. 3 port network
C. 4 port network
D. None of the mentioned
Answer: B
Clarification: A T junction is a 3 port network where the junction is excited at one of the port, output is measured at another port, with the third port terminated with a known impedance.

3. A T junction has a 3×3 ‘s’ matrix.
A. True
B. False
Answer: A
Clarification: ‘n’ port microwave network is represented as n×n s matrix. Characteristics of a microwave network can be known by analyzing his s matrix. A T junction has 3 ports. Hence, they are represented as a 3×3 matrix.

4. If a device is passive and contains no anisotropic elements, then the device is_______ network.
A. Reciprocal
B. Non reciprocal
C. Lossless
D. Lossy
Answer: A
Clarification: If a device is passive, it does not store any energy and does not contain any sources. It then acts as a reciprocal network. That is, when the input and output ports are interchanged, the power delivered remains the same.

5. Scattering matrix of a reciprocal network is:
A. Symmetric
B. Asymmetric
C. Identity matrix
D. Null matrix
Answer: A
Clarification: For a reciprocal network, when the output and input ports are interchanged/ the power delivered remains the same. Hence in the S matrix Sij=Sji. This condition is satisfied by a matrix that is symmetric.

6. If all the ports of a microwave network are matched, then the diagonal elements of the S matrix of the network is zero.
A. True
B. False
Answer: A
Clarification: When all the ports of a microwave network are matched, no power is reflected back to the port that is excited by the source. Since no power is reflected back, the elements Sii of the S matrix become zero.

7. If a microwave network is lossless, then S matrix of the microwave network is:
A. Unitary
B. Symmetric
C. Identity matrix
D. Zero matrix
Answer: A
Clarification: If a microwave network is lossless, law of energy conservation requires that the condition for example, │S12│2+│S13│2= 1. This condition has to be satisfied for a 3 port network. This can be generalized for any n port network.

8. A lossless reciprocal 3 port network can be matched at all the three ports.
A. True
B. False
Answer: B
Clarification: A lossless three port network can be only matched at 2 ports. It not possible for the S matrix of a 3 port network to satisfy all the above conditions .This would violate the law of conservation of energy.

9. A circulator is a 3 port network that allows energy flow in clockwise direction only.
A. True
B. False
Answer: B
Clarification: A circulator is a 3 port device that allows energy flow in only one direction. The direction of flow is either clockwise or counter clockwise. Bothe the directions are not simultaneously allowed in a circulator.

10. The diagonal elements of the S matrix of an improperly matched circulator is zero.
A. True
B. False
Answer: B
Clarification: If the three ports of a circulator are not properly matched, it would result in the backward flow of power to the previous ports. Hence, the diagonal elements will not be zero due to improper matching as they signify the reflection of energy back to the same port.

11. Coupling factor of a directional coupler must be maximum and is a key factor that determines the performance of the coupler.
A. True
B. False
Answer: A
Clarification: Coupling factor indicates the fraction of input power that is coupled to the output port. If a directional coupler has higher coupling factor, maximum power is obtained at the output port with low loss.

12. Directivity of a directional coupler signifies the direction of power flow in the coupler.
A. True
B. False
Answer: B
Clarification: Directivity is the measure of the directional coupler’s ability to isolate forward and backward waves. Directivity is also defined as the ratio of power at the output port to the power at the isolated port.

13. Isolation of a directional coupler is a measure of the:
A. Power delivered to the uncoupled port
B. Power delivered to the coupled port
C. Power delivered to the second port
D. None of the mentioned
Answer: A
Clarification: In a directional coupler, there exists a port called the isolated port through which no power is received and is isolated from the remaining ports of the coupler. Isolation of a directional coupler is a measure of the power delivered to the uncoupled port.

14. Insertion loss is the power delivered to the through port.
A. True
B. False
Answer: A
Clarification: In a directional coupler, the second port is called is called the through port and the third port is called the output port. When power flows from port 1 to output port, the power measured at port 2 can be termed as insertion loss.

15. In a symmetric coupler, the power delivered to the through port and output port are equal.
A. True
B. False
Answer: A
Clarification: A symmetric coupler is the one which delivers equal amount of power to both port 2 and port 3 of the directional coupler. The signals t these ports are out of phase by 900.


Microwave Engineering,