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| 2. |
- Egard, Mikael, et al.
(författare)
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20 GHz gated tunnel diode based UWB pulse generator
- 2009
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Ingår i: Physica Status Solidi C: Current Topics In Solid State Physics, Vol 6, No 6. - 1610-1634. ; 6:6, s. 1399-1402
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Konferensbidrag (refereegranskat)abstract
- We demonstrate a pulse generator based on a GaAs-AlGaAs gated resonant tunneling diode (RTD). This is realized by integrating a third terminal, the gate, into the current path of a RTD. The gate consists of a 200 A thick tungsten grating buried 300 A above the RTD. This implementation allows for control of the current through the RTD. By integrating this device in parallel with an on-chip inductance, a negative differential resistance (NDR) oscillator is formed. It is demonstrated that by using the gate to change the output conductance of the device, the oscillations may be switched on and off, creating short bursts of RF power. This technique allows for rapid quenching of the oscillator, and hence the ability to generate short pulses at high frequency, enabling impulse radio ultra-wideband communication implementations. The highest demonstrated oscillation frequency is 22 GHz with an output power of -4.1 dBm, and the shortest pulses generated are 1.3 ns. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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| 3. |
- Egard, Mikael, et al.
(författare)
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20 GHz Wavelet Generator Using a Gated Tunnel Diode
- 2009
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1531-1309. ; 19:6, s. 386-388
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate the use of a GaAs-AlGaAs gated tunnel diode (GTD) in an ultra-wideband (UWB) wavelet generator. An inductor is integrated to form an oscillator circuit, which is driven by the negative differential conductance property of a GTD. It is demonstrated that as the gate tunes the magnitude of the output conductance, the oscillator may be switched on and off, creating short RF pulses. The shortest pulses generated are 500 ps long, the highest output power for the free running oscillator is -4.1 dBm, and the highest oscillation frequency is 22 GHz. Analytical expressions based on the van der Pol equation describing the pulse length and amplitude are presented. This technique is applicable for high frequency impulse radio UWB implementations.
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| 4. |
- Egard, Mikael, et al.
(författare)
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60 GHz Wavelet Generator for Impulse Radio Applications
- 2009
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Ingår i: European Microwave Conference, 2009. EuMC 2009. - 9781424447480 ; , s. 1908-1911, s. 234-237
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Konferensbidrag (refereegranskat)abstract
- A wavelet generator producing 100 ps short pulses at 60 GHz is presented. The wavelet generator consists of a gated tunnel diode (GTD) integrated in parallel with an inductor. This forms a negative differential conductance (NDC) oscillator with the ability to switch the NDC property on and off, which makes it possible to generate short pulses. In the experiments described, the wavelet generator drives a 50 Omega load and delivers 206 mV(pp) when generating 97 ps short pulses at 60 GHz. It Is demonstrated that it is possible to generate pulses of different length and phase. An explanation of the almost instantaneously startup and decay lapse of the oscillator, including generation of signals with opposite phase, is presented. This novel circuit may find use in ultra-wideband impulse radio communication.
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| 5. |
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| 6. |
- Egard, Mikael, et al.
(författare)
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Bias Stabilization of Negative Differential Conductance Oscillators Operated in Pulsed Mode
- 2011
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480. ; 59:3, s. 672-677
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Tidskriftsartikel (refereegranskat)abstract
- The paper reports on the bias stabilization of a 60-GHz resonant-tunneling diode (RTD)-based oscillator operated in pulsed mode. The oscillator contains an on-chip stabilizing capacitor, enabling the minimum dc consumption possible for such an RTD oscillator to be obtained, since all of the dc current is consumed by the active device. This is achieved without imposing restraints on the output power or introducing parasitic oscillations in the bias network. The oscillator that was constructed produces short 75-ps wavelets at 60 GHz, at an energy consumption of 1.3 pJ, during generation of a pulse. Experimental, simulated, and analytical results are presented for demonstrating how this mode of operation can be utilized in negative differential conductance oscillators.
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| 7. |
- Egard, Mikael, et al.
(författare)
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Frequency Modulation in mm-Wave InGaAs MOSFET/RTD Wavelet Generators
- 2013
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Ingår i: 2013 International Conference on Indium Phosphide and Related Materials (IPRM). - 1092-8669. ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- Co-integration of an InGaAs MOSFET and an RTD is performed to realize a wavelet generator. The large transconductance of the MOSFET (1.9 mS/mu m) is used to switch the current in an oscillator circuit and coherent wavelets down to 41 ps are generated in the frequency domain of 50 to 100 GHz. The lowest power consumption measured is 1.9 pJ/pulse. It is found that the supply bias can be used to modulate the center frequency of the wavelets.
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| 8. |
- Egard, Mikael, et al.
(författare)
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Gated tunnel diode pulse generator
- 2008
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Ingår i: Technical report MC2 - Department of Microtechnology and Nanoscience, Chalmers University of Technology. - 1652-0769. ; :nrMC2-125, s. 37-37
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Konferensbidrag (refereegranskat)
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| 9. |
- Egard, Mikael, et al.
(författare)
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Gated Tunnel Diode with a Reactive Bias Stabilizing Network for 60 GHz Impulse Radio Implementations
- 2010
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Ingår i: Device Research Conference (DRC), 2010. - 1548-3770. ; , s. 161-162
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Konferensbidrag (refereegranskat)abstract
- We report on a gated tunnel diode (GTD) and its operation in a 60 GHz pulsed oscillator, also known as a wavelet generator. The wavelet generator operates with the aid of a reactive bias stabilizing network, which minimizes the DC power consumption. This allows for 60 GHz wavelets as short as 56 ps to be produced, with a corresponding energy consumption of 1.0 pJ, which is a factor of 3.6 lower as compared to earlier results. The operation of the GTD is described by a small signal equivalent model deduced from S-parameter measurements.
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| 10. |
- Egard, Mikael, et al.
(författare)
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High-Frequency Performance of Self-Aligned Gate-Last Surface Channel In0.53Ga0.47As MOSFET
- 2012
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Ingår i: IEEE Electron Device Letters. - 0741-3106. ; 33:3, s. 369-371
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a self-aligned L-g = 55 nm In-0.53 Ga-0.47 As MOSFET incorporating metal-organic chemical vapor deposition regrown n(++) In0.6Ga0.4As source and drain regions, which enables a record low on-resistance of 199 Omega mu m. The regrowth process includes an InP support layer, which is later removed selectively to the n(++) contact layer. This process forms a high-frequency compatible device using a low-complexity fabrication scheme. We report on high-frequency measurements showing f(max) of 292 GHz and f(t) of 244 GHz. These results are accompanied by modeling of the device, which accounts for the frequency response of gate oxide border traps and impact ionization phenomenon found in narrow band gap FETs. The device also shows a high drive current of 2.0 mA/mu m and a high extrinsic transconductance of 1.9 mS/mu m. These excellent properties are attributed to the use of a gate-last process, which does not include high temperature or dry-etch processes.
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