Kale, Agarwal, and Aurobindo wards the noise floor, are the result of amplitude shaping in a time domain with a Tukey window with roll-off factor of 0.10. The spurs seen at an offset of ±10 MHz are approximately 60 dB down relative to power level at 1.4 GHz and hence do not cause interference issues while transmitting. These spurs are found to be present in the spectrum prior to mixer and are possibly DDS dependent. The spectrum of one of the phase coded waveforms, a 13-bit Barker code, is shown in Figure 9. The typical sin(x)/x shape of a fill-in pulse's spectrum can be seen in Figure 10. The spectral mainlobe width, i.e., the first null-to-null width, of a fill-in pulse and a phase coded waveform is inversely proportional to its pulse width and bit-duration, respectively. The same can be verified from Figure 9 and Figure 10. Figure 9. Spectrum of 13-bit Barker code (Tb = 0.5μs) at 1.4 GHz. Figure 10. Spectrum of 0.5 μs long fill-in pulse at 1.4 GHz. DECEMBER 2018 IEEE A&E SYSTEMS MAGAZINE 23