| 1. |
- Alzaher, H. A., et al.
(författare)
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CMOS digitally programmable filter for multi-standard wireless receivers
- 2000
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 36:2, s. 133-135
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Tidskriftsartikel (refereegranskat)abstract
- A technique for designing digitally programmable CMOS integrated filters for multi-standard wireless receivers is presented. The technique exhibits the wide frequency range of the transconductance amplifier filters while offering improved linearity. It utilises digitally controlled current followers to provide precise frequency characteristics that can be tuned over a wide range. A digitally tuned lowpass filter is designed for implementing the channel-select filter in the baseband chain of a multi-standard CMOS wireless receiver. Simulation and experimental results obtained from a 1.2 mu m chip show a programmable frequency response covering the IS-54, GSM, IS-95 and WCDMA wireless standards.
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| 2. |
- Alzaher, H. A., et al.
(författare)
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CMOS fully differential second-generation current conveyor
- 2000
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 36:13, s. 1095-1096
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Tidskriftsartikel (refereegranskat)abstract
- The design of a CMOS fully differential second generation current conveyor is presented. The proposed circuit was designed to incorporate the current sensing technique into a fully differential version of a differential difference amplifier (DDA). A low power class AB circuit realisation has been implemented in 1.2 mu m CMOS technology. A variable gain amplifier (VGA) designed to incorporate the circuit has been shown to exhibit constant, low power consumption and constant, wide bandwidth at different gain settings. Experimental results of the proposed circuits are presented.
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| 3. |
- Alzaher, H. A., et al.
(författare)
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Digitally tuned analogue integrated filters using R-2R ladder
- 2000
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 36:15, s. 1278-1280
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Tidskriftsartikel (refereegranskat)abstract
- A new technique for designing digitally tuned frequency selective analogue integrated circuits is proposed. The technique incorporates the R-2R ladder as a circuit element into the circuit design to provide precise frequency characteristics that can be tuned over a wide range. Two filters are described to illustrate the proposed approach. The proposed filters are used to implement the channel-select filter of a multi-standard direct conversion wireless receiver and the bandpass filter of a low IF frequency-hopping receiver.
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| 4. |
- Alzaher, H., et al.
(författare)
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CMOS baseband filter for WCDMA integrated wireless receivers
- 2000
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 36:18, s. 1515-1516
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Tidskriftsartikel (refereegranskat)abstract
- A new second-order lowpass filter based on a single CMOS fully differential current conveyor is presented. Developed from the Sallen-Key highpass filter, the proposed filter is AC coupled and provides programmable gain. Moreover, the filter exhibits low noise, high linearity and low power, making it suitable for implementing the baseband filter of a WCDMA direct-conversion wireless receiver. A WCDMA filter having a programmable bandwidth around 2.1 MHz, a variable gain rang of 50dB and a DC notch below 2kHz using passive components below 5kW for resistors and 20pF for capacitors is implemented. Experimental and simulation results obtained from fabricated chips are included.
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| 5. |
- Andreani, Pietro
(författare)
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Very low phase noise RF quadrature oscillator architecture
- 2001
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 37:5 July, s. 902-903
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Tidskriftsartikel (refereegranskat)abstract
- An architecture for RF quadrature oscillators is presented, which, according to simulations, shows a figure of merit some 20 dB higher than that of other quadrature oscillators. The new quadrature oscillator compares favourably even with a state-of-the-art design of the popular negative-resistance differential oscillator
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| 6. |
- Asplund, Carl, et al.
(författare)
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1260 nm InGaAs vertical-cavity lasers
- 2002
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 38:13, s. 635-636
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Tidskriftsartikel (refereegranskat)abstract
- The fabrication and performance of highly strained double-quantum well InGaAs/GaAs vertical-cavity lasers with record-long emission wavelength of 1260 nm at room temperature is reported. Depending on device diameter, the minimum threshold current is in the low mA-regime while the maximum output power exceeds 1 mW. The devices work continuous-wave over a wide temperature range of at least 10-120degrees C.
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| 7. |
- Barrios, C. A., et al.
(författare)
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GaAs/AlGaAs buried-heterostructure vertical-cavity surface-emitting laser with semi-insulating GalnP : Fe regrowth
- 2000
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Ingår i: Electronics Letters. - 0013-5194 .- 1350-911X. ; 36:18, s. 1542-1544
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Tidskriftsartikel (refereegranskat)abstract
- The authors report the first results of a GaAs/AlGaAs buried-heterostructure vertical-cavity surface-emitting laser (VCSEL) with semi-insulating Ga0.51In0.49P:Fe (SI-GaInP:Fe) as the burying layer. Regrowth of SI-GaInP:Fe around 15 mu m diameter and 8 mu m tall VCSEL mesas was carried out by hydride vapour phase epitaxy (HVPE). Under room temperature continuous wave (CW) operation. the device exhibited a threshold current of 3.5mA, a differential quantum efficency of 33% and a light output power of 4.2mW. CW operation at temperatures up to 97 degrees C is also demonstrated.
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| 8. |
- Bjurshagen, Stefan, et al.
(författare)
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Generation of blue light at 469 nm by efficient frequency doubling of a diode-pumped Nd:YAG laser
- 2002
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 38:7, s. 324-325
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Tidskriftsartikel (refereegranskat)abstract
- Efficient operation of a diode-pumped Nd: YAG laser at 938.5 nm is reported. A continuous wave output power of 3.9 W is obtained. Single-pass frequency doubling in periodically poled KTP delivered a power of 88 mW at 469 nm. By intracavity frequency doubling an output of 200 mW in the blue region is achieved.
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| 9. |
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| 10. |
- Claesson, A., et al.
(författare)
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Diode-pumped miniature lasers using microstructured silicon carriers
- 2000
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 36:5, s. 433-434
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Tidskriftsartikel (refereegranskat)abstract
- A new versatile design concept for compact diode-pumped solid-state lasers based on a microstructured silicon carrier with etched V-grooves is presented. The carrier provides efficient thermal management as well as compact integration and alignment of all active acid passive optical components. In initial experiments, an Nd:YAG laser delivered a continuous-wave output of 3W.
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