ECEP 322 Semi-Final Exam

What factor most limits the use of conventional components at microwave frequencies?

• High power requirements

• Line-of-sight constraints

• Component parasitic effects

• Signal propagation velocity

Which transmission medium is preferred above 6 GHz due to low loss and high confinement?

• Coaxial cable

• Microstrip

• Optical fiber

• Waveguide

Why are waveguides typically made from copper or aluminum?

• For thermal conductivity

• To enhance magnetic field containment

• To reduce signal reflection

• To minimize resistance and losses

How does a hybrid ring differ from a traditional microstrip circuit?

• It cannot split signals

• It allows two-way communication only

• It's optimized for power amplification

• It enables signal splitting and combining

Which parameter of a waveguide directly controls its cutoff frequency?

• Flare angle

• Inner diameter

• Width of cross-section

• Wave impedance

In microwave receivers, what role does the LNA (low-noise amplifier) play?

• Reduces the noise of IF signals

• Amplifies high-frequency signals with minimal added noise

• Converts RF signals to baseband

• Detects microwave energy

What feature of a parabolic antenna contributes most to its high gain?

• Aperture area

• Feed horn location

• Focal length

• Beam width

What differentiates a Gunn diode from a typical PN-junction diode?

• Absence of a depletion region

• Use of P-type silicon

• Lack of a junction

• Bidirectional operation

What characteristic makes helical antennas especially suitable for low-cost designs?

• Adjustable phase shift

• Minimal component count

• Frequency independence

• Simple mechanical structure

What physical design allows MMICs to perform efficiently at microwave frequencies?

• Use of optical substrates

• Three-layer semiconductors

• Ultra-thin plastic encapsulation

• Integrated microstrip circuits