An RF transmitter is proposed for 3-5 GHz time-hopping ultra wideband（TH-UWB） wireless applications.The transmitter consists of a 4-GHz oscillator, a switch with a controllable attenuator and an output matching circ...An RF transmitter is proposed for 3-5 GHz time-hopping ultra wideband（TH-UWB） wireless applications.The transmitter consists of a 4-GHz oscillator, a switch with a controllable attenuator and an output matching circuit.Through controlling the low frequency signals with time-hopping pulse position modulation（TH-PPM）, the circuit supplies TH-UWB signals and can directly drive an antenna by a transmission line.The transmitter was implemented in a 0.18-μm CMOS technology;the output amplitude is about 65 mV at a 50 ？ load from a 1.8-V supply, the return loss（S 11） at the output port is less than-10 dB, and the chip size is 0.7 × 0.8 mm2, with a power consumption of 12.3 mW.展开更多
The paper analyzes power spectral density (PSD) of orthogonal pulse-based signals for time hopping ultra wideband (TH-UWB) systems. Our extensive studies show that the PSD of these signals not only depends on the time...The paper analyzes power spectral density (PSD) of orthogonal pulse-based signals for time hopping ultra wideband (TH-UWB) systems. Our extensive studies show that the PSD of these signals not only depends on the time dithering code and the modulation schemes, but also on the energy spectral density (ESD) of orthogonal pulses. The different order orthogonal pulses provide different ESD which changes the shape of continuous spectral component with symbols. We show that orthogonal pulse-based signals reduce the dynamic range of amplitude of discrete spectral components. Further, we reduce the dynamic range by adopting longer TH code over orthogonal pulse-based signals. As a result, UWB system performance improves with average transmitted power. The theoretical analysis of PSD of orthogonal pulse-based TH-UWB signal is provided in details and verified through simulation results.展开更多
基金supported by the National High Technology Researchand Development Program of China(No.2007AA03Z454)the Scienc Foundation of Guangxi Province, China (No. 0575096)
文摘An RF transmitter is proposed for 3-5 GHz time-hopping ultra wideband（TH-UWB） wireless applications.The transmitter consists of a 4-GHz oscillator, a switch with a controllable attenuator and an output matching circuit.Through controlling the low frequency signals with time-hopping pulse position modulation（TH-PPM）, the circuit supplies TH-UWB signals and can directly drive an antenna by a transmission line.The transmitter was implemented in a 0.18-μm CMOS technology;the output amplitude is about 65 mV at a 50 ？ load from a 1.8-V supply, the return loss（S 11） at the output port is less than-10 dB, and the chip size is 0.7 × 0.8 mm2, with a power consumption of 12.3 mW.
文摘The paper analyzes power spectral density (PSD) of orthogonal pulse-based signals for time hopping ultra wideband (TH-UWB) systems. Our extensive studies show that the PSD of these signals not only depends on the time dithering code and the modulation schemes, but also on the energy spectral density (ESD) of orthogonal pulses. The different order orthogonal pulses provide different ESD which changes the shape of continuous spectral component with symbols. We show that orthogonal pulse-based signals reduce the dynamic range of amplitude of discrete spectral components. Further, we reduce the dynamic range by adopting longer TH code over orthogonal pulse-based signals. As a result, UWB system performance improves with average transmitted power. The theoretical analysis of PSD of orthogonal pulse-based TH-UWB signal is provided in details and verified through simulation results.
