This product comes from Alaris Antennas catalogues

Quick Deployment Active HF NVIS DF Element


The DF-A0172 antenna is a single site location (SSL) Active HF DF array element. Polarisation is selectable between linear vertical, RHCP and LHCP though the injecting of different DC voltages into the circular interface connector The antenna includes a low noise pre-amp that increases the antenna sensitivity, an integrated switching system and lightning and ESD protection. In passive bypass mode, there are no nonlinear active components in the chain to introduce unwanted distortion on the received signals. It can be deployed as part of either a linear or circular array and is quickly and easily deployed and stowed. The product is unique in that it features a fully integrated quadpod for rapid deployment but can also be bolted to a plinth for semi-permanent installations. When stowed, the antenna collapses into a very small form factor for easy transportation and storage. The design of the antenna element is such that it is able to switch between one of three modes: LHCP, RHCP and a VP omni mode. In LHCP and RHCP modes, the antenna element is capable of receiving waves of LHCP and RHCP polarisation respectively, incident from the upper half sphere, with a gain peak at Œ? = 0° (directly upwards). In VP omni mode, the antenna operates similar to a monopole antenna, able to receive waves with vertical polarisation with a gain peak on the horison (or just above it) and a null at Œ? = 0°. The antenna is intended for use in constructing DF interferometer arrays consisting of a number of DF-A0172 antennas.

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Frequency range 1 - 30 MHz
VSWR < 2.0:1 (typical CP modes)
Nominal impedance 50 O
RF power handling Receive only
Polarisation Linear
Power supply 12 V
OIP3 (Active mode) 38 dBm
Switching cycles Designed for 100 Mc
Total height (deployed/stowed) < 2250/1200 mm
Temperature range Designed for storage: -30 °C to +70 °C De
Temperature range Designed for operation -30 °C to +55 °C
Weatherproofing Designed for IP66 rain resistant
Shock and vibration Designed for MIL-STD 810E 516.4: vibration category 8
Wind resistance 120 km/h without guy ropes 160 km/h when fitted with guy ropes
Exposed materials Painted aluminium and fibreglass

    Product Applications

    Signals Intelligence
  • Radio Direction Finding
  • C-ESM

    Design Features

  • Low visual profile Quick deployment Active operation with passive bypass option Integrated switching system Lightning/ESD protected Compact stowed form factor