Receiver Protectors

e2v has been manufacturing receiver protectors for over 30 years and offers a range of solid-state receiver protection products for S, X and Ka band civil and military marine, coastal & weather radars.

Receiver protectors isolate the sensitive receiver from the damaging levels of RF power present when the RF source transmits. When this power is no longer present, they go into a low-loss state, allowing the RF echoes to pass through to the receiver for amplification and detection. They typically comprise one or more PIN diode stages to protect sensitive receivers from synchronous (transmitter) and non-synchronous interference damage.

e2v offer a range of low noise front ends for both X and S band radars. They comprise a Low Noise Amplifier (LNA), a mixer and a voltage controlled oscillator (VCO) local oscillator to provide down conversion to an intermediate frequency.

Figure 1 is the schematic for a single stage. By cascading a number of the diode stages with filters, an increased level of RF attenuation and low magnitude of RF leakage can be achieved.

The illustration in figure 2 shows such an arrangement with the package PIN diode mounted on a sliding short circuit choke, secured on two threaded boss structures within the waveguide wall. This structure also shows a filter section designed to attenuate magnetron spurious signals.

 

Fig 1: basic single stage schematic

Fig 2: example of multistage assembly

 

Product Features

e2v receiver protectors include options for:
• Power handling
• Out of band filtering
• Self bias (within limiter with rectified current from RF pulse)
• Self bias (from integral detector)
• Waveguide pressure windows (to meet airborne requirements)

Further Option for radar systems
• STC stage for Rx blanking
• STC trigger ( enable by logic pulse)
• Noise diode stage (as part of a system RX calibration function)

Key Interface Specifications
Electrical:
Frequency Range:  Multiple sub bands @ X & S band as detailed in data sheets

Environmental:
Temperature (operational):  Typ -20 ? +85 ?C       


Mechanical:
Outlines: as datasheets,
Mass: 100 g approx (X band)