3151 Log Periodic Dipole Array

3151 Log Periodic Dipole Array

Frequency Range: 20 MHz – 220 MHz The Model 3151 Foreshortened Log Periodic Dipole Antenna features a convenient space-saving design with the use of top hat-loaded, low-frequency elements. This reduced-sized design has optimized impedance loading to simulate the moderate gain of a full-size LPDA. Without size reduction, the longest dipole element length would be approximately 7.5 m (24.6 ft). Instead, the Mode l3151’s entire width is only 3.5 m (11.5 ft).To enhance measurement repeatability, the Model 3151’s longest elements are supported with nylon straps to ensure consistent element positioning. The 3151 antenna features a specially-designed feed to handle high power requirements of up to 5 kW for generating high electric field strength. A hairpin matching stub is used to improve the low-frequency VSWR, which minimizes mismatch loss between the amplifier and antenna. The included wheeled pedestal permits horizontal and vertical antenna polarization, and tilt-angle adjustments. A pneumatic cylinder is used to change polarization, and can be remotely controlled using an optional ETS-EMCO Model 2090 Controller or an ETS-EMCO 2190 Virtual Controller. The Model 2090 is IEEE-488 compatible, and uses fibre optic I/O for communication with the pedestal.   Electrical Specifications

Frequency Maximum 220 MHz
Frequency Minimum 20 MHz
Pattern Type Directional
Polarization Linear

Key Features

  • 20 MHz to 220 MHz frequency range
  • High power feed handles up to 5 kW RF input power
  • Space saving design features top hat-loaded, low-frequency elements
  • Mounted on wheeled base for easy mobility

Application Notes