Mats Ärlelid

Slot-Coupled Millimeter-Wave Dielectric Resonator Antenna for High-Efficiency Monolithic Integration

A readily mass-producible, flip-chip assembled, and slot-coupled III-V compound semiconductor dielectric resonator antenna operating in the millimeter-wave spectrum has been fabricated and characterized. The antenna has a 6.1% relative bandwidth, deduced from its 10 dB return loss over 58.8–62.5 GHz, located around the resonance at 60.5 GHz. Gating in the delay-domain alleviated the analysis of the complex response from the measured structure. The radiation efficiency is better than

20 GHz Wavelet Generator Using a Gated Tunnel Diode

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Coherent V-Band Pulse Generator for Impulse Radio BPSK

dB in simulations fed from the on-chip coupling-structure, but reduced by 3.7 dB insertion loss through the measurement assembly feed. Antenna gain measurements show distortion in relation to the simulated pattern, which has a maximum gain of 6 dBi, mainly caused by interference from the electrically large connector used in the assembly. Mode degeneration in the utilized quadratic-footprint resonator was not seen to influence the performance of the antenna. The antenna is intended for on-chip integration and the fabrication technology allows scaling of the operation frequency over the complete millimeter-wave spectrum.

High-Frequency Performance of Self-Aligned Gate-Last Surface Channel MOSFET

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.

High-Frequency Performance of Self-Aligned Gate-Last Surface Channel In0.53Ga0.47As MOSFET

A coherent pulse generator for implementation in an impulse radio system is presented. It accurately transforms a 12.5 GHz square wave input signal to 33 ps long 60 GHz pulses. The wavelets are generated through direct conversion from baseband to 60 GHz by switching a negative differential conductance oscillator on and off. The slope of the input signal determines the phase, which is either I + or I -. The generator is feasible for use in coherent radio systems since the method shows consistent startup and decay of the generated wavelets. The coherence between the input baseband signal and wavelet output signal is demonstrated in an eye diagram with rms jitter <; 1.3 ps. The oscillator is implemented with a gated resonant tunneling diode where the input level also can be used to tune the center frequency of the wavelets.

60 GHz ultra-wideband impulse radio transmitter

We have developed a self-aligned L_g = 55 nm In_0.53Ga_0.47As MOSFET incorporating metal-organic chemical vapor deposition regrown n⁺⁺ In_0.53Ga_0.47As source and drain regions, which enables a record low on-resistance of 199 Ωμm. 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/μm and a high extrinsic transconductance of 1.9 mS/μm. These excellent properties are attributed to the use of a gate-last process, which does not include high temperature or dry-etch processes.

RTD–MOSFET Millimeter-Wave Wavelet Generator

We have developed a self-aligned L_g = 55 nm In_0.53Ga_0.47As MOSFET incorporating metal-organic chemical vapor deposition regrown n⁺⁺ In_0.53Ga_0.47As source and drain regions, which enables a record low on-resistance of 199 Ωμm. 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/μm and a high extrinsic transconductance of 1.9 mS/μm. These excellent properties are attributed to the use of a gate-last process, which does not include high temperature or dry-etch processes.

60 GHz wavelet generator for impulse radio applications

An impulse radio transmitter at 60 GHz with pulse duration time down to 100 ps is reported. OOK modulation is presented and the results show promise for other modulation schemes. The transmitter consists of a gated tunnel diode in parallel with a coplanar waveguide, which is a design that provides direct conversion from the baseband pulse train to radio frequency wavelets with a center frequency of 60 GHz. This is achieved by turning an oscillator on and off. Pulse repetition rate up to 2 Gpulses/s is measured and the pulse data shows extremely short start up and decay time.

A 60 GHz super-regenerative oscillator for implementation in an impulse radio receiver

We report on the fabrication of a self-aligned regrown In0.53 Ga0.47As metal-oxide-semiconductor field-effect transistor (MOSFET) and a resonant tunneling diode (RTD). The performance of these devices is demonstrated by integrating them in parallel with an inductive coplanar waveguide stub to form a highly energy-efficient 70-GHz wavelet generator. The fast switching and low on-resistance of the MOSFET make it possible to kick-start and rapidly quench this RTD-driven oscillator circuit, which produces 41-ps-short wavelets at 15 Gpulses/s, a peak output power of 7 dBm, and an energy consumption of 1.9 pJ/pulse.

High-Frequency Performance of Self-Aligned Gate-Last Surface Channel

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 Ω load and delivers 206 mVpp 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.