17-03-2014, 09:26 PM
Abstract— A target simulator based on the digital RF memory
(DRFM) is presented in this paper. The simulator consists of a
interface unit which is controlled by MCU, a high-precision
calculation DSP unit, a DRFM unit based on FPGA, and
corresponding microwave unit. This target simulator has
simple circuits, high precision and stability. The integrated
testing results with a seeker proved that the system
successfully simulates the echo of the moving points target and
can be used for verifying the tacking ability of the seeker.
Key Words: Target simulation; Radio frequency
simulation; DSP; FPGA; DRFM
I. INTRODUCTION
With the precision of guidance weapons improving, the
complexity and cost of range tests rise rapidly. RF
simulation is a method to simulate the information
generated by the environment and target of radar guidance
seekers when the missile is flying, so that the performance
of the missile is tested without the real missile launched. In
the process of development and measurement of guidance
weapons, RF simulation can improve the performance of
guidance weapons, and decrease the cost of development
and measurement by reducing the number of the real
missile launched. There are some reports of radar target
simulators, e.g. hardware-in-the-loop simulation for
guidance seeker in Russia, and radar IF echo simulator
based on DDS[1].
Here we present a target simulator for guidance seeker
applying digital RF memory (DRFM) and DSP technique
and verify its performance. This target simulator has the
advantage of simple circuits, high precision and stability.
II. THE THEORY OF THE TARGET SIMULATOR
The radar equation can be written as[3]
2 1
2
3 4 0 [ ] ( )exp[ 2 ( )( )]
(4 ) d Sr G u t j f f t r
R
?
? ? ?
?
? ? ? ?
········ (1)
From this equation, we can see that the echo received by
radar guidance seeker includes some information of the
target. The information of echo mainly contains the delayed
time, the Doppler frequency and the power attenuation,
which are affected by the target’s distance, velocity and
RCS character.
The purpose of the simulator designed in this paper is
mainly applied for testing the distance tracking performance.
The system can simulate the delay and the attenuation of
target echo.