Publication Date


Document Type


Committee Members

Henry Chien-in (Advisor), Marian Kazimierczuk (Committee Member), Saiyu Ren (Committee Member)

Degree Name

Master of Science in Engineering (MSEgr)


Digital microwave receivers play a critical role in many of today's modern radar tracking systems. The need for these digital receivers to push the boundaries in terms of bandwidth and input dynamic ranges (DR) is vital for their use in radar signal tracking. Significant research has been conducted in the area of the fast Fourier transform (FFT) to aid in continuing to enhance the performance capabilities of digital microwave receivers. However, with the advancement and increased complexity of these systems, the need for an efficient and effective adaptive thresholding technique is becoming ever more present.

The proposed adaptive thresholding technique utilizes signal magnitude evaluations and multi-stage signal scaling throughout a 128-point FFT in order to effectively determine the optimal threshold for the microwave receiver. The incorporation of a 10-bit dynamic kernel function, as well as 14-bit word size between FFT stages is used to aid in increasing receiver sensitivity, multi-tone instantaneous dynamic range (IDR) and spurious free dynamic range (SFDR) performance.

With the implementation of our adaptive thresholding technique, our receiver's maximum IDR is maintained between 34dB down to 24dB for input signal strengths ranging from -4dBm down to -32dBm. From simulation results incorporating the use of digitized data from our 10-bit Atmel ADC our Multi-Stage Scaling (MSS) receiver design is capable of obtaining an SFDR of 35.91dB using an input signal strength of -7dBm.

Page Count


Department or Program

Department of Electrical Engineering

Year Degree Awarded