AN3: Millimeter-Wave Sensitive Receivers

Applications: Millimeter wave receivers as a class are essential part of virtually every millimeter wave based subsystem, particularly radiometers, radar and radios. However, several applications utilize a highly sensitive receiver to achieve the ultimate primary function of the system. 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

The architecture of a typical sensitive receiver subsystem is shown in Figure 1 for reference.

Figure 1(a)
Broadband Sensitive Receiver

Figure 1(b)
Typical Broadband Sensitive Receiver Architecture

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
Table and Figure

Frequency Ranges Description and Features Applications
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.
1-18 GHz
MMW and Sub-MMW
Cryogenically-cooled receivers with cooled amplifiers Radio astronomy, radiometry, Spectrometry (O3, etc.)
55-65 GHz Ultra low noise receiver uses state of the art MMW LNA and broadband mixer For environmental measurement
140-152 GHz Local oscillator at 134 GHz with 6-18 GHz IF. Noise figure of 9 dB typical (uncooled) Plasma measurement system


QuinStar Components and Products Used: Balanced Mixer
Frequency Multipliers
Microwave (IF) Amplifiers – Cooled and Room Temperature
Millimeter Wave Amplifiers (Low Noise, Power)
Oscillators (Gunn Diode Oscillator, series QTM from 18-150 GHz)
Power Dividers/Hybrids (Short Slot Coupler, Matched Hybrid Tee, Directional Couplers)