A kind of architecture of Time-to-Digital Converter(TDC) for Ultra-WideBand(UWB) application is presented. The proposed TDC is based on pulse shrinking, and implemented in a Field Programmable Gate Array(FPGA) device....A kind of architecture of Time-to-Digital Converter(TDC) for Ultra-WideBand(UWB) application is presented. The proposed TDC is based on pulse shrinking, and implemented in a Field Programmable Gate Array(FPGA) device. The pulse shrinking is realized in a loop containing two Programmable Delay Lines(PDLs) or a two-channel PDL. One line(channel) delays the rising edge and the other line(channel) delays the falling edge of a circulating pulse. Delay resolution of PDL is converted into a digital output code under known conditions of pulse width. This delay resolution measurement mechanism is different from the conventional time interval measurement mechanism based on pulse shrinking of conversion of unknown pulse width into a digital output code. This mechanism automatically avoids the influence of unwanted pulse shrinking by any circuit element apart from the lines. The achieved relative errors for four PDLs are within 0.80%–1.60%.展开更多
In this paper,an Ultra-Wideband(UWB) planar antenna is proposed for the reinforced concrete detection,which consists of a pair of planar waterdrop arms,a microstrip to coplanar parallel-strips transition and a shallow...In this paper,an Ultra-Wideband(UWB) planar antenna is proposed for the reinforced concrete detection,which consists of a pair of planar waterdrop arms,a microstrip to coplanar parallel-strips transition and a shallow rectangular cavity.In order to overcome the disadvantages of the shallow cavity,some absorbing material is loaded to weaken the narrow-band effect of the cavity and the crosstalk interference.The simulated and measured results show that the proposed antenna has a large bandwidth from 0.48 GHz to 3.6 GHz with Voltage Standing Wave Ratio(VSWR) below 2 and a fractional bandwidth about 200% under the center frequency of 1.6 GHz,directional radiation characteristics and small late-time ringing in the time domain,which can be suitable for nondestructive detection of the reinforced concrete.展开更多
基金Supported by the National High Technology Research and Development Program(No.2012AA121901)
文摘A kind of architecture of Time-to-Digital Converter(TDC) for Ultra-WideBand(UWB) application is presented. The proposed TDC is based on pulse shrinking, and implemented in a Field Programmable Gate Array(FPGA) device. The pulse shrinking is realized in a loop containing two Programmable Delay Lines(PDLs) or a two-channel PDL. One line(channel) delays the rising edge and the other line(channel) delays the falling edge of a circulating pulse. Delay resolution of PDL is converted into a digital output code under known conditions of pulse width. This delay resolution measurement mechanism is different from the conventional time interval measurement mechanism based on pulse shrinking of conversion of unknown pulse width into a digital output code. This mechanism automatically avoids the influence of unwanted pulse shrinking by any circuit element apart from the lines. The achieved relative errors for four PDLs are within 0.80%–1.60%.
基金Supported by the National High Technology Research and Development Program(No.2012AA061403)
文摘In this paper,an Ultra-Wideband(UWB) planar antenna is proposed for the reinforced concrete detection,which consists of a pair of planar waterdrop arms,a microstrip to coplanar parallel-strips transition and a shallow rectangular cavity.In order to overcome the disadvantages of the shallow cavity,some absorbing material is loaded to weaken the narrow-band effect of the cavity and the crosstalk interference.The simulated and measured results show that the proposed antenna has a large bandwidth from 0.48 GHz to 3.6 GHz with Voltage Standing Wave Ratio(VSWR) below 2 and a fractional bandwidth about 200% under the center frequency of 1.6 GHz,directional radiation characteristics and small late-time ringing in the time domain,which can be suitable for nondestructive detection of the reinforced concrete.
