Abstract: Infrared communications scheme for use in an embedded system. According to a preferred embodiment, the invention comprises the use of an infrared communications scheme, according to IrDA protocol, which is utilized to transmit and receive data via an electrical interface between circuit cards housed within an enclosed, embedded system. Preferably, each respective circuit card is provided with a digital tri-stateable transmitter element and a digital receiver to respectively transmit and receive data. The systems and methods of the present invention provide increased reliability than prior-art systems and methods.

Abstract: An unattended ground sensor for the monitoring of a remote area. The unattended ground sensor comprises a housing that supports a power source, a communications module, at least one sensor module and a mainframe module. Additionally, the unattended ground sensor includes a common electrical bus in electrical communication with the power source, the communications module, the at least one sensor module, and the mainframe module. The common electrical bus is operative to provide a communications pathway between the power source, the communications module, the at least one sensor, and the mainframe module. Accordingly, the mainframe module is operative to control the operation of the unattended ground sensor through the common electrical bus.

Abstract: A moving target simulator for testing a radar system has a radio frequency receiver, a digital radio frequency memory in electrical communication with the radio frequency receiver for storing a signal received thereby, a digital delay circuit in electrical communication with the digital radio frequency memory for providing a time delay between reception and transmission of the radio frequency signal, an amplitude modulation circuit in electrical communication with the digital radio frequency memory for modulating an amplitude of the radio frequency signal, a Doppler modulation circuit in electrical communication with the digital radio frequency memory for providing a Doppler-modulated signal, and a radio frequency transmitter for transmitting the radio frequency signal after it has been delayed, amplitude-modulated, and/or Doppler-modulated.

Abstract: A continuous wave diplex Doppler radar, comprising an oscillator generating a transmit signal having a spectrum at a carrier frequency, the oscillator having a frequency control input, and spread spectrum modulation means coupled to the frequency control input for spreading the spectrum of the transmit signal.

Abstract: A low cost RF link is implemented by summing a wideband amplitude noise dither signal with a band limited RF signal. The summed signal is then amplitude limited. The output of the limiter can be applied directly to the digital fiber optic transmitter. At the remote end of the link, the original signal can be recovered by removing the noise dither signal. This can easily be accomplished with a narrow band filter centered on the original signal. This system uses the same optical fiber transmitters and receivers as the traditional system, but eliminates the need for the ADCs, DACs and parallel/serial format conversion hardware. Adding amplitude dither to the signal mitigates the intermodulation distortion that would normally be associated with the non-linear operation of amplitude limiting. In this way, multiple narrow band signals can be transmitted down a single fiber using digital fiber optic transmitters and receivers without distortion due to intermodulation.