🔍 Key Concepts

• How mixer current is produced in a radar receiver-mixer stage • What happens to mixer current if the local oscillator is not properly tuned • How TR (transmit-receive) cell problems or mixer diode condition might affect signal and current

💭 Think About

• Ask yourself: which of these components, if not working correctly, could reduce the RF or LO signal reaching the mixer, and therefore reduce mixer current? • Think about whether the problem must be in only one place, or could different types of faults in different parts of the front end all lead to the same symptom (low mixer current). • For each option, imagine the signal path from antenna to mixer and ask: does this fault reduce or block energy at the mixer junction?

✅ Before You Answer

• For each choice, decide: could this realistically reduce the RF or LO signal level at the mixer? • Consider whether TR cell failure affects only transmit, only receive, or both, and how that ties to mixer current. • Check if mixer diode degradation would change the diode’s ability to rectify/mix signals and therefore its current.