LPDP-80-1300

The LPDP-80-1300 is a versatile, high-power Dual Polarized Log Periodic Dipole Antenna (LPDA) designed for wideband directional communication across the 80–1300 MHz spectrum. Covering everything from VHF to L-Band, this cross-element array provides independent vertical and horizontal feeds. Its robust, foldable design makes it an ideal solution for tactical jamming, signal monitoring, and high-gain transmission where polarization agility is required to capture both E and H polarized signals simultaneously.

Design: Wideband Polarization Mastery

The LPDP-80-1300 is engineered to eliminate the "polarization mismatch" common in multi-agency and tactical environments. By integrating two independent orthogonal arrays on a single set of support booms, the antenna offers:

• Dual Port Independence: Features 2 x N-Female terminations, allowing for simultaneous vertical and horizontal signal processing.
• No-Loss Array: Unlike smaller "loaded" antennas, this LPDA uses full-length elements to ensure maximum radiation efficiency and a consistent 8 dBi gain across the entire 80–1300 MHz range.
• Center-Mount Balance: Designed with a center-of-gravity mounting arrangement to ensure stability on tactical masts, even with its substantial 2.2-meter length.

Construction: Tactical Logistics & Durability

Despite its impressive 2.2-meter (7.2 feet) overall length, the LPDP-80-1300 is built for transportability.

• Foldable & Segmented Elements: Radiating elements are supplied in two segments and utilize a foldable design to reduce shipping volume. The longest element is 0.95 meters.
• Military Finish: Metal surfaces are treated with an epoxy-based olive green powder coating, providing superior protection against UV radiation, salt fog, and chemical corrosion.
• Marine-Grade Hardware: All fasteners, including the center mounting clamps, are made from high-strength stainless steel. The antenna is D.C. grounded, offering a low-resistance path to protect against lightning and suppress atmospheric noise.

Reliability: 250W Multi-Mission Performance

With a 250 Watt power capacity, the LPDP-80-1300 is a powerhouse for wideband electronic countermeasures (ECM). It maintains an 80-degree beamwidth and a 16 dB Front-to-Back ratio, ensuring that energy is concentrated toward the target while protecting the operator's site from self-interference. It is rated for extreme wind speeds of 190 Km/Hr, making it suitable for permanent coastal installations or temporary tactical deployments.

Technical Features

• Dual-Polarized Cross-Element Geometry: Captures both horizontal and vertical signal components simultaneously.
• Elite 80–1300 MHz Bandwidth: Covers VHF, UHF, GSM, and L-Band within a single directional array.
• High-Efficiency Radiators: No loading coils or resistors used; provides true 8 dBi directional gain.
• Foldable Tactical Design: Segemented elements allow for easier logistics and rapid field assembly.
• 250W Continuous Duty Power: Engineered for high-duty cycle jamming and backbone communications.
• Integrated Lightning Protection: D.C. grounded design ensures safety and low noise for sensitive receivers.
• Military 6063T6 Aluminum Construction: Anodized and powder-coated for 20+ year environmental survival.
• Center Mounting Clamp: Fits up to 52mm (2-inch) pipe; provides balanced load distribution on masts.
• High Front-to-Back Ratio: 16 dB F/B ratio ensures maximum energy is directed at the target area.
• Corrosion Resistant: All stainless steel hardware prevents "seizing" in coastal or humid environments.

ECM & Monitoring Guide: 80–1300 MHz Polarization & Signal Intercept

The LPDP-80-1300 is a strategic asset for Electronic Countermeasures (ECM) and Signal Intelligence (SIGINT) because it covers the transition from traditional VHF tactical radio (80–174 MHz) to modern UHF, GSM, and L-Band data links (400–1300 MHz). In these high-speed environments, the antenna's dual-polarization is the key to maintaining a "constant lock" on frequency-hopping targets.

1. Defeating Polarization "Fading" in Tactical VHF

At the lower end of the band (80–150 MHz), tactical manpack and vehicle radios predominantly use vertical whips. However, in dense urban or heavily forested environments, signals bounce (multipath) and rotate their polarization.

• The "Null" Problem: A single vertical antenna may experience a signal drop of up to 20 dB if the incoming wave has rotated horizontally due to reflections.
• The Dual-Port Solution: By monitoring both the Vertical and Horizontal ports of the LPDP-80-1300, a SIGINT system can "see" the signal on the horizontal plane even when it disappears on the vertical. This ensures a continuous intercept of high-priority voice and data bursts.

2. High-Power Jamming Success Rate (ECM)

When jamming frequency-hopping targets in the 400–1300 MHz range, the goal is to saturate the victim's receiver.

• Saturating the "E" and "H" Planes: Many modern data links use complex antenna arrays. If your jammer is only vertically polarized, the enemy can often maintain a link by switching to a horizontally polarized backup or through "cross-pol" leakage.
• 250W Total Coverage: Feeding 250W into the LPDP-80-1300 allows you to transmit high-intensity noise on both polarizations. This leaves the target radio with no "clean" orientation to receive its intended signal, effectively raising the noise floor across all possible antenna positions.

3. SIGINT "Look-Through" & Mode Analysis

Strategic monitoring requires identifying the type of transmitter, not just its frequency.

• Polarization "Fingerprinting": * Vertical Dominance: Usually indicates mobile tactical units, maritime vessels, or ground-based circular whips.
  • Horizontal Dominance: Often indicates fixed-site point-to-point links, television/broadcast backup, or specialized NVIS VHF links.
• Mode Analysis: By comparing the phase and amplitude of the two ports, an operator can determine if a signal is coming from a moving vehicle (rapid polarization shifts) or a static base station (stable polarization).

4. Directional Precision & "Front-to-Back" Isolation

The 80-degree beamwidth of the LPDP-80-1300 acts like a wide-angle searchlight.

• Target Acquisition: It is wide enough to find a frequency-hopping signal without needing to point the antenna with surgical precision.
• Protecting Friendly Comms: The 16 dB Front-to-Back ratio is critical in the 80–1300 MHz range. It prevents the 250W jamming signal from leaking backward and interfering with your own command-and-control (C2) receivers located behind the antenna.

Tactical SIGINT Deployment Checklist

• Phase-Matched Feeders: For advanced diversity combining (MRC), use identical lengths of low-loss coaxial cable (e.g., LMR-400) for both the V and H ports to ensure no phase offset is introduced by the cabling.
• Center-Mount Balance: Ensure the mounting mast is vertical. Because the LPDP-80-1300 is 2.2 meters long, a slight tilt will significantly degrade the Cross-Polarization Discrimination at frequencies above 800 MHz.
• Connector Weatherboarding: In the UHF/L-Band (400–1300 MHz), even a tiny amount of moisture in the N-Female connector will cause massive VSWR spikes. Always use butyl rubber and UV-rated electrical tape for sealing.
• Safe Working Distance: At 250 Watts, the 80-degree "Main Lobe" is a high-intensity RF hazard area. Ensure the antenna is mounted at least 5 meters above any personnel working in the vicinity.