The impact of mutual coupling on MIMO radar emissions

2012 IEEE Radar Conference

Cook

et al. 2012

Ongoing work is exploring the optimization of physical radar emissions based on the continuous phase modulation (CPM) implementation of polyphase codes. Here a modification to the code search strategy known as Marginal Fisher's Information (MFI) is presented that enables this greedy approach to further improve upon the performance of the resulting CPM-implemented continuous waveform in terms of range sidelobes. The optimization process is also expanded to include the effects of the transmitter (from both modeled and physical hardware perspectives) to facilitate the optimization of physical emissions that are specifically tuned to the transmitter. This approach is particularly useful for high-power transmitters in which the actual physical emission is a spectrally modified and non-linearly distorted version of the intended radar waveform.

Section: Introductionmentioning

confidence: 99%

Transmitter-in-the-loop optimization of physical radar emissions

Jakabosky

2012 IEEE Radar Conference

Cook

et al. 2012

“…Including the entire system in the optimization allows for the final physical radar waveform to account for distortion introduced by transmitters, antennas, and even platform effects. Antenna and platform effects are particularly important when considering, for example, how mutual coupling impacts MIMO radar emissions [10]. This paper considers all effects through the transmit antenna.…”

Section: Emissions Optimization Paradigmmentioning

confidence: 99%

Hardware-in-the-loop radar waveform optimization using radiated emissions

Seguin

Jakabosky

2013 IEEE International Symposium on Electromagnetic Compatibility

2013

Self Cite

A truly holistic approach to electromagnetic compatibility should include waveform design and diversity, especially when considering high-power radar systems. One current challenge is producing a radar waveform that is physically realizable and that is optimized for a radar's actual hardware, including the chosen antennas. This work explores the optimization of physical radar radiated electromagnetic emissions based on the continuous phase modulation (CPM) implementation of polyphase codes along with a greedy search for the code search strategy. Multiple metrics for designing the waveform such as the peak sidelobe level (PSL), and integrated sidelobe level (ISL), were used during the optimization process. The optimization of the radar's waveform includes the effects of the entire transmit chain, including the antenna by measuring the actual electromagnetically radiated emissions of the radar.

“…Mutual coupling effects are also known to distort MIMO emissions [19,20]. Therefore care must be taken when antenna elements are electrically close (less than half-wavelength spacing), which tends to increase coupling between elements.…”

Section: Reactive Vs Radiated Powermentioning

confidence: 99%

Joint spectrum/beampattern design of wideband FM MIMO radar emissions

McCormick

2016 IEEE Radar Conference (RadarConf)

Metcalf

2016

Self Cite

The co-design of multiple-input multiple-output (MIMO) radar waveforms and the associated beampattern is desirable to maximize transmitted power in directions of interest while still maintaining acceptable waveform correlation properties. While MIMO is an emerging technology in radar, one must also consider the stringent spectral requirements that are currently being imposed now and that may become even more stringent in the future. In this paper a MIMO optimization method based on alternating projections is introduced that optimizes, for a uniform linear array, the constant-modulus, continuous-time, element-level waveforms to produce a spectral shape in various desired spatial directions denoted "beams of interest". The resulting beampattern is directly related to these chosen "beams of interest". To address the physical nature of the MIMO emission, the energy stored in the invisible space (i.e. not radiated into the far-field) is considered. It is shown that this stored energy, which could damage the transmitter if operated at high power, can effectively be minimized by optimizing the beampattern based on the visible emission space.