Tom K. Johansen

Learn More
We construct a coordinate-independent description of oscillator linear response through a decomposition scheme derived independently of any Floquet theoretic results. Trading matrix algebra for a simpler graphical methodology, the text will present the reader with an opportunity to gain an intuitive understanding of the well-known phase noise macromodel.(More)
This paper describes a quadrature voltagecontrolled oscillator (QVCO), frequency doubler, and subharmonic mixer (SHM) for a millimeter-wave (mm-wave) frontend implemented in a high-speed InP DHBT technology. The QVCO exhibits large tuning range from 38 to 47.8 GHz with an output power around -15 dBm. The frequency doubler is based on a novel feedback(More)
The dynamic equations governing the cross-coupled quadrature harmonic oscillator are derived assuming quasi-sinusoidal operation. This allows for an investigation of the previously reported tradeoff between close-to-carrier phase noise and quadrature precision. The results explain how nonlinearity in the coupling transconductances, in conjunction with a(More)
This paper reports on a novel balanced HBT sub-harmonic mixer (SHM) for E-band wireless communication. An LO spiral type Marchand balun is integrated with the SHM. The SHM has been fabricated in a InP double heterojunction bipolar transistor (DHBT) circuit-oriented technology with fr/fmax = 180GHz/200GHz. The measured results demonstrates a(More)
Within PANTHER research project, we aim to develop multi-rate, multi-format, multi-reach and multi-flow terabit transceivers for data-center gateways, having the capability of flexibly controlling this enormous capacity and distributing it among independent optical flows. To this end, we combine electro-optic with passive polymers and we develop a novel(More)
We present a comprehensive nonlinear analysis of coupled oscillators and examine the trade-off between phase-noise of the oscillator and the quadrature precision. We show that asymmetry gives rise to amplitude and phase imbalance which are proportional to the inverse and inverse square, respectively, of the relative coupling strength. It is shown that the(More)
The paper presents analysis and design of a -band subharmonic mixer (SHM) with high conversion gain. The SHM consists of a local oscillator (LO) frequency doubler, RF pre-amplifier, and single-ended mixer. The SHM has been fabricated in a high-speed InP double heterojunction bipolar transistor (DHBT) technology using coplanar waveguide structures. To the(More)
In this paper, the design and modeling of InP DHBT based millimeter-wave(mm-wave) power amplifiers is described. This includes the modeling of InP DHBT devices and layout parasitics. An EM-circuit co-simulation approach is described to allow all parasitics to be modeled for accurate circuit performance evaluation. A single-branch cascode based PA using(More)