A monolithic voltage controlled oscillator （VCO） based on negative resistance principle is presented uti-lizing commercially available InGaP/GaAs hetero-junction bipolar transistor （HBT） technology. This VCO is de...A monolithic voltage controlled oscillator （VCO） based on negative resistance principle is presented uti-lizing commercially available InGaP/GaAs hetero-junction bipolar transistor （HBT） technology. This VCO is de-signed for 5GHz-band wireless applications. Except for bypass and decoupled capacitors,no external component is needed for real application. Its measured output frequency range is from 4.17 to 4.56GHz,which is very close to the simulation one. And the phase noise at an offset frequency of 1MHz is -112dBc/Hz. The VCO core dissipates 15.5mW from a 3.3V supply,and the output power ranges from 0 to 2dBm. To compare with other oscillators,the figure of merit is calculated,which is about -173.2dBc/Hz. Meanwhile, the principle and design method of nega-tive resistance oscillator are also discussed.展开更多
This paper proposes a new multitarget constant modulus array structure for code division multiple access (CDMA) systems. The new algorithm for the structure is called pre-despreading and wavelet denoising constant mod...This paper proposes a new multitarget constant modulus array structure for code division multiple access (CDMA) systems. The new algorithm for the structure is called pre-despreading and wavelet denoising constant modulus algorithm (D-WD-CMA). In the new algorithm, the pre-despreading is applied to multitarget arrays to remove some multiple access inter- ferences. After that the received signal is subjected to wavelet de-noising to reduce some noise, and used in CMA adaptive iteration for signal separation. Simulation results showed that the proposed algorithm performed better than the traditional CMA algorithm.展开更多
文摘A monolithic voltage controlled oscillator （VCO） based on negative resistance principle is presented uti-lizing commercially available InGaP/GaAs hetero-junction bipolar transistor （HBT） technology. This VCO is de-signed for 5GHz-band wireless applications. Except for bypass and decoupled capacitors,no external component is needed for real application. Its measured output frequency range is from 4.17 to 4.56GHz,which is very close to the simulation one. And the phase noise at an offset frequency of 1MHz is -112dBc/Hz. The VCO core dissipates 15.5mW from a 3.3V supply,and the output power ranges from 0 to 2dBm. To compare with other oscillators,the figure of merit is calculated,which is about -173.2dBc/Hz. Meanwhile, the principle and design method of nega-tive resistance oscillator are also discussed.
基金Project supported by the National Natural Science Foundation of China (No. 60372107) and the Hi-Tech Research and Development Program (863) of China (No. 2002AA121068)
文摘This paper proposes a new multitarget constant modulus array structure for code division multiple access (CDMA) systems. The new algorithm for the structure is called pre-despreading and wavelet denoising constant modulus algorithm (D-WD-CMA). In the new algorithm, the pre-despreading is applied to multitarget arrays to remove some multiple access inter- ferences. After that the received signal is subjected to wavelet de-noising to reduce some noise, and used in CMA adaptive iteration for signal separation. Simulation results showed that the proposed algorithm performed better than the traditional CMA algorithm.
