FPGA based flexible UWB pulse transmitter using EM subtraction

Abstract

An all-digital field programmable gate array based electromagnetic subtraction technique for direct UWB pulse generation is presented. Using this technique, it is possible to generate Gaussian pulses, monocycles or doublets with high flexibility using a single printed circuit board layout. User-controlled parameters include amplitude, pulsewidth, pulse-type, repetition rate or even modulation. Measurements indicate a Gaussian pulse with 1.24 V peak amplitude and a 10% pulse-width of 670 ps can be transmitted at a repetition frequency of 100 MHz. The corresponding − 10 dB bandwidth is 2.8 GHz.Introduction: Over the past decade, UWB radio has been commonly proposed for short-range high data rate communications [1] or for radar applications in the industrial [2] and medical fields. However, widespread implementation is still ongoing. This Letter contributes to providing an easy implementable development platform for UWB signal generation with higher flexibility compared with other transmitters. The key innovation of the Letter is the usage of a field programmable gate array (FPGA) together with an electromagnetic (EM) subtraction technique to form different Gaussian pulse shapes in a direct way. Two general transmitter implementations exist to date. CMOS integrated circuits can be considered for full-custom designs, while on the other hand, transmitters can be composed using commercial off-the-shelf components. The latter are implemented with step recovery diodes (SRDs) [2] or mesfets to generate steep edges and provide flexibility to some extent. An all-digital FPGA based implementation combines the high flexibility of CMOS designs together with rapid and easy implementation.

Optimal Central Frequency for Non-Contact Vital Sign Detection Using Monocycle UWB Radar

“…In impulse radio ultra-wideband (IR-UWB) radar applications, one of the most simple-to-generate transmitting pulses is monocycle waveform, as illustrated in Figure 1a. The waveform defined as the first derivative of the Gaussian pulse can be easily generated by microwave circuits or FPGA boards with low distortion [14][15][16][17][18][19][20][21][22][23][24][25]. In time domain, the amplitude, s(t), of the monocycle waveform is defined as [20][21][22]…”

Highly adjustable mixer‐based UWB pulse generator architecture with leakage compensation integrated in 40 nm CMOS

“…1). This technique was also used in [9, 10]. Here, a baseband pulse is generated and upconverted to the desired UWB frequency band.…”

“…This unwanted signal will generate a spur, at the VCO frequency, in the upconverted pulse spectrum. This effect is discussed and minimised in [11] and can also be seen in the generated UWB pulses of [9, 10]. In [11], the UWB pulse is generated by switching the VCO signal.…”