http://eurekaaerospace.com/hpems.php

Technology Description

The high-power electromagnetic system (HPEMS) uses microwave energy to disable/damage vehicle’s electronic control module/microprocessors which control engine’s vital functions. The system is capable of (1) high-value asset perimeter protection from approaching hostile vehicles, (2) bringing cars to halt on urban, suburban roads and multi-lane highways, (3) perimeter protection for gas-oil (fueling) platform at sea and (4) day/night, all weather clandestine operations. Figures shown here depict HPEMS’ application for stopping vehicles on highways and perimeter protection of gas-oil fueling platform from approaching boats at sea.

The focus originally is to build a compact portable tunable system to be integrated in a police car (Ford Crown Victoria) and having the following operational capabilities:

• Operational range of frequencies tunable in the 350-1350 MHz range
• Immobilizing all vehicles with microprocessors at the range exceeding 50 meters
• HPEMS fits on a roof of a vehicle

Once the car-hosted system is built and tested, Eureka Aerospace will transition the technology to building larger HPEMS for 5-km perimeter protection applications.

HPEMS consists of 3 major elements:

1. Power Source
2. Tunable RF Oscillator
3. High-gain antenna

The power source consists of 16-stage Marx generator having erected voltage in excess of 640 kV, generating high energy (103 J each) pulses at PRF=100 Hz, yielding 10 kW average power. Marx generator is being fed by 270 Vdc capacitor bank, which in turn is energized by a 12V, 2kJ/sec car alternator. The design goal is to achieve PRF=1000 Hz, thus increasing the average power by 10 dB.

Tunable RF Oscillator consists of a two-plate variable length transmission line and a fast (less than 100 ps) closing spark-gap switch, which traps the pulses between the switch and the antenna (load) and thus converts Marx’s dc energy into microwave energy at a frequency controlled by the length of the transmission line.

High-gain antenna constitutes an integral part of the oscillator, since it represents the load of the oscillator circuit. Its terminals are connected to the transmission line and it radiates due to the oscillating voltage on its terminals. In the development of antenna subsystem, the key elements are: (1) suitable impedance allowing for efficient radiation and yet permitting adequate oscillations to occur between the switch and antenna for having large Q, (2) antenna size and shape for achieving required gain and yet not be obtrusive. The candidate antennas include (a) horn, (b) spiral and (c) Impulse radiating antenna (IRA), with gain ranging from 16 dBi (at 350 MHz) to 28 dBi (at 1.35 GHz). The operational system will have multiple (HH and VV) or circular polarization.

Tunable oscillator together with a high-power switch constitutes an integral part of the entire HPEMS. The subsystem will be tunable in the 350-1350 MHz range, where the most vulnerable frequencies for vehicles were determined during Phase II effort. The choice of a dielectric medium inside the switch, which will be based on the magnitude of the maximum voltage on its electrodes, the size of the gap between electrodes together with antenna impedance, will be selected to achieve the most efficient power transfer from Marx generator to the radiating antenna. Moreover, to accommodate large voltages, the option of using multi-channel switch oscillator system is being investigated. The overall objective of the HPEMS is to deliver at least 20 kV/m at the target vehicle of up to 50 m.

Finally, to avoid collateral damage to other vehicles, particularly on multi-lane highways, HPEMS is designed to optimize the antenna beam size, given operational frequency and the limitations of the antenna aperture size, which, together with system operational procedures (distance to the target vehicle and aspect angle) will assure the “illumination” of the target vehicle only. The tables below cite 1) HPEMS features, advantages, and benefits and 2) HPEMS comparison with other key competing technologies.

All current vehicle stopping systems, although affordable but highly ineffective, can be replaced by Eureka’s HPEMS.

No interfacing equipment or facilities are needed for implementation of HPEMS technology.

Current State of Development

In April 2004, Eureka Aerospace conducted a series of tests at the Los Angeles Sheriff Department’s (LASD) Fleet maintenance facility, where the so-called vulnerable frequencies associated with the microprocessor pins controlling the most vital function of the Electronic Control Modules (ECMs) were measured for six vehicles including Chevy Lumina, Dodge truck, Ford Taurus, Ford Crown Victoria, Toyota 4Runner and Nissan Maxima. This, in turn, will allow for the optimum design of the HPEMS. Figure on the right presents a sample of the measurement results - frequency response of the Dodge Dakota’s ignition switch for both H and V-polarizations. Note the resonances at 760 and 1,250 MHz, which indicate that these are the “vulnerable” frequencies for this vehicle – clearly an optimal choice of HPEMS’ operational frequencies in this particular case.

The determination of vehicle’s "vulnerable" frequencies plays a key role in the developing of an optimal high-power microwave system, resulting in the reduction of the system requirements on the radiated power, system size and weight.

Earlier, Eureka Aerospace developed system concepts for both 5-km perimeter protection and vehicle immobilization on highways, where detailed analysis of the HPEMS and design curves for power and aperture requirements were carried out.

Currently, a prototype HPEMS to be hosted by a Ford Crown Victoria is being fabricated at Eureka’s microwave laboratory with anticipated completion by October 2005, and subsequent full-scale tests in November 2005 at Los Angeles Sheriff’s Department’s (LASD) range facility. The Current Technology Readiness Level (TRL) is 6.
The next step would be the development of a larger HPEMS system for MARCORSYSCOM and OPNAV(Navy) to be deployed on top of the building and oil-gas fueling platform, respectively, for a 5-km perimeter protection purpose.