Efficient HF Submarine Antennas

Presenters Frank Plonski of HI-Q-Antennas Charles M. Gyenes of HI-Q-Antennas JULY 10, 2008

Overview

• • • Background - Abstract/Problem/Solution Antenna - Design parameters/Description Performance - Data/Measured/Calculated/results

ABSTRACT

For submarine applications, it is desirable to have broadband, efficient, extremely short HF antennas that can cover the whole band without the use of a complex internal/external tuning circuitry. A short monopole antenna is currently used except that it has the following disadvantages: it is not efficient and uses complex external tuning circuitry. An electrically efficient small packaged submarine antenna that operates at the HF band was developed using existing subminiature aperture technology.

In this paper, we detail the HF submarine antenna technology and performance results focusing on existing efficient submarine HF communications antennas.

PROBLEM

• • • • Hard to achieve efficient HF performance in small restricted Radome cylindrical size Current HF submarine antennas are very inefficient radiators Complex antenna couplers decreases reliability and increases maintenance Heat exchangers removing non-radiated RF generated heat are undesirable

SOLUTION

(installed on HMS Gotland) • • • • HI-Q-4/2-30 installed on HMS Gotland Submarine HF Communications Antenna HI-Q antenna has higher radiation efficiency then any other short HF submarine antenna designed to date HI-Q antenna has only one moving part No external complex antenna couplers

Design Parameters

PARAMETER Volume Frequency VSWR Power Radiation Patterns Gain Impedance Polarization HMS GOTLAND REQUIREMENT 92 X 4.0 inches 2-30 MHz 1.5:1 Nominal 500 watts Omni-directional in Azimuth @ 2.0 MHz -12dBi Minimum rising to + 4.5 dBi @ 30 MHz 50 ohm Vertical HI-Q ANTENNA DELIVERED 92 X 4.0 inches 2-30 MHz 1.5:1 Nominal 1500 watts Omni-directional in Azimuth @ 2.0 MHz -12dBi Minimum rising to + 4.5 dBi @ 30 MHz 50 ohm Vertical

Antenna Description

( Specific to the HMS GOTLAND) • HI-Q-4/2-30 is a broadband, ultra small HF aperture, 2-30 MHz tunable antenna • Inductively tuned from 2-20 MHz Re Entrant Coaxial Capacity Hat antenna, a very broadband monopole from 20- 30 MHz. • Antenna consists of a lower mast, a tunable loading coil, a Re-Entrant Capacity Hat, and an antenna controller.

• Remotely tunable (5 sec) with +24vdc motor or a stepper motor

DIMENSIONS AND MASS

( Specific to the HMS GOTLAND) • Total height: inches max (includes connectors) 92 • Diameter: inches max (includes screw-bolt heads) 4 • Weight: lbs (approx) 20

HI-Q-Family of Submarine Antennas

HI-Q-6-2/30 HI-Q-5-2/30 HI-Q-4-2/30 HMS GOTLAND

HI-Q-4/2-30 Measured VSWR

( Specific to the HMS GOTLAND)

Computed Radiation Pattern and Gain

HMS Gotland HF Antenna Installation

Antenna Performance

• • • 2- way worldwide communications achieved using HI-Q-6/2-30MHz Virginia Class prototype Demonstrated high Radiation Efficiency by 2- way communications (5x9) EXAMPLES: 1.850 MHz USA and Canada (2006 2007 winter),3.795 MHz From near San Diego California to Hawaii, China, Japan, Australia, New Zealand, 3.798 MHz to South Africa, 7.250 MHz daily contacts within USA, Canada, Europe, 14-18.0- 21.0 MHz world wide with 100 watt RF SSB

CONCLUSIONS

• • • • In this paper we have reviewed some of our calculated and experimental results on design of electrically short HF antennas. The HI-Q antenna has higher radiation efficiency then any other short HF submarine antenna designed to date. High Reliability – one moving part Very COST Effective

Acknowledgments

NAVSEA-PHL contributing team members on the Hi-Q antenna integration into the HMS GOTLAND Submarine sub-safe mast Mr. James Stiles of NSWC-CD Philadelphia Mr. John Ledder of NSWC-CD Philadelphia Mr. John Dolan of NSWC-CD Philadelphia Mr. Jason Batcho of NSWC-CD Philadelphia Mr. Frank Plonski of NSWC-CD Philadelphia Mr. Allan Heong of GDIT- Philadelphia