Future radar systems will need to be adaptive and reconfigurable to allow for adequate sharing of the spectrum with wireless communication systems. This chapter has described several algorithms that facilitate the optimization of transmitter circuitry andradarwaveforms. The goals of these approaches include (1) ensuring desiredradar range/Doppler resolution characteristics, (2) achieving high powerPAE, and (3) spectral compliance to minimize the interference to other spectrum users. Algorithms for the fast tuning of the power amplifier load impedance, as well as simultaneous tuning of load impedance with input power or bias voltage, have been demonstrated to locate the optimal solution within a feasible number of required measurements.

Chapter Contents:

• 12.1 Why an adaptive and reconfigurable radar transmitter?
• 12.1.1 Traditional radar spectrum regulations
• 12.1.2 Dynamic spectrum access
• 12.2 Algorithms for circuit optimization
• 12.2.1 Optimization of load impedance to maximize PAE under spectral constraints
• 12.2.2 The Smith tube
• 12.2.3 Simultaneous optimization of load impedance and input power using the power Smith tube
• 12.2.4 Simultaneous optimization of load impedance and bias voltage using the bias Smith tube
• 12.2.5 Optimization of PAE under multiple constraints based on output power and ACPR
• 12.3 Radar waveform optimization with spectral mask compliance
• 12.3.1 Woodward's ambiguity function
• 12.3.2 Alternating projections optimization
• 12.4 Adjusting the radar spectral mask based on surrounding wireless devices
• 12.4.1 Calculation of a dynamic radar spectral mask
• 12.4.2 Radar waveform optimization using a dynamic spectral mask
• 12.4.3 Joint transmitter and waveform optimization
• 12.5 Looking ahead
• 12.5.1 Creating a regulatory environment favoring adaptive radar transmission
• 12.5.2 Cooperation between radar and communication systems
• 12.5.3 Development of high-power-tunable components
• 12.6 Conclusions
• Acknowledgments
• References

Inspec keywords: radiofrequency amplifiers; minimisation; radar transmitters; electromagnetic interference

Other keywords: spectral compliance; Doppler resolution characteristics; fast tuning; adequate sharing; transmitter amplifier; transmitter circuitry; bias voltage; power amplifier load impedance; wireless communication systems; interference minimization; real-time optimization; high power-PAE; future radar systems; transmitter waveforms; adaptively reconfigurable radar; desired radar range

Subjects: Radio and television receivers; Amplifiers; Electromagnetic compatibility and interference; Radar equipment, systems and applications; Optimisation techniques