Product Application Notes – Millimeter-Wave Sensitive Receivers
Millimeter-wave receivers as a class are an essential part of virtually every millimeter wave based subsystem, particularly radiometers, radar, and radios. However, several applications use a highly sensitive millimeter-wave receiver to achieve the ultimate primary function of the system. As an illustration, principal examples of such applications are:
- Electronic Warfare (EW), Electronic Support Measure (ESM)
- Direction Finding/Radar Threat Warning Systems
- Radioastronomy, Plasma Physics, Molecular Chemistry (Spectrometers)
- Compliance measurement (Communication, Safety, Regulatory)
- Electronic Surveillance, ELINT
Below, Figure 1 shows the architecture of a typical sensitive receiver subsystem.
Operation and Typical Performance Characteristics
Plot of Noise Figure vs. freq. for different types of receivers (inc. cooled). And fundamental limits.
Typical Examples and Case Histories
||Description and Features
|From 30 to 110 GHz (in approximately 20 GHz bands)
||Single aperture provides extremely broadband signal to a set of receivers that cover full range in 20 GHz bands with unique local oscillator scheme. Low noise figure with high spurious-free dynamic range.
||Electronic Warfare, ESM receiver, Direction Finding, Radar Threat Detection.
MMW and Sub-MMW
|Cryogenically cooled receivers with cooled amplifiers
||Radio astronomy, radiometry, Spectrometry (O3, etc.)
||Ultra low noise receiver uses state of the art MMW LNA and broadband mixer
||For environmental measurement
||Local oscillator at 134 GHz with 6-18 GHz IF. Noise figure of 9 dB typical (uncooled)
||Plasma measurement system
Microwave (IF) Amplifiers – Cooled and Room Temperature
Millimeter-Wave Amplifiers (Low Noise, Power)
Oscillators – Gunn Diode Oscillator: QTM
Power Dividers/Hybrids (Short Slot Coupler, Matched Hybrid Tee, Directional Couplers)