Jan H Mikkelsen

This review explores the progress of spin-wave technology, emphasizing magnonics as a potential solution to modern challenges in radio frequency (RF) communication systems. To ensure clarity, the first two sections of the review reiterate premises of the magnonics, outline key milestones in spin-wave research, briefly review the state-of-the-art fo...

Accurate measurements of the intrinsic ferromagnetic linewidth of a single-crystal Sc-doped hexagonal M-type barium ferrite (BaM) 308-micron-diameter sphere at millimeter-wave frequencies employing a subwavelength cavity are described. The magnetic hysteresis of the resonance frequency and Q-factor of the dominant resonance (which has a plasmonic c...

Wireless earbuds have become the preferred electronic device for listening to music and for hands-free talking. The combined radio performance of the earbud and the handset determines the quality of the established communication link and hence the quality of the user experience. This paper presents an extensive comparative study of five common Blue...

A pattern reconfigurable Yagi antenna based on liquid metal is presented. The antenna consists of a balun-fed active dipole and a pair of stretchable passive parasitic dipoles, which are implemented by EGaIn alloy embedded in microfluidic channels. The parasitic dipoles are driven at each end by two low-cost, 3-D printed media rods. Afterwards, spi...

This paper presents an ultra-wideband band-pass filter designed using a slot-line ring resonator and two pairs of embedded circular slot structures. The slot-line ring resonator is used to form the desired UWB passband, and the upper stop-band response is suppressed by embedding the circular slot structures into the ring resonator. This is differen...

This paper presents an algorithm for the generation of a multisine signal capable of accurately mimicking bandwidth and first order statistics such as the probability density function and the peak-to-average power ratio (PAPR) of an arbitrary digitally modulated signal. The implemented algorithm outperforms state-of-the-art multisine design procedu...

This brief presents an ultra-wideband pulse generator topology featuring adaptive control of power spectral density for a broad range of applications with different data rate requirements. The adaptivity is accomplished by employing a limited monocycle precharge approach to control the energy used for pulse generation at different desired data rate...

New advanced Envelope Tracking (ET) techniques can provide RF (radio frequency) transmitters with high-efficiency power amplifiers (PAs). On the other hand, system complexity substantially increases, requiring more advanced PA models for the representation and compensation of ET PA distortion effects. In this context, this paper proposes some solut...

This letter proposes a UWB pulse generator topology featuring low peak power dissipation for applications with stringent instantaneous power requirements. This is accomplished by employing a new slow-charge fast-discharge approach to extend the time duration of the generator's peak current so that the peak value of the current is significantly redu...

This study presents a method to characterise thermal resistances and capacitances of GaN high-electron-mobility transistors (HEMTs) through dynamic electrothermal measurements. A measured relation between RF gain and the channel temperature (Tc) is formed and used for indirect measurements of dynamic Tc responses. Thermal resistances and capacitanc...

Developments within modern nonlinear measurement systems offer an increasing degree of flexibility to the microwave power amplifier (PA) designer. The PA designer has historically been a driving factor in setting the development directions of new measurement systems, fueling the paradigm, that PA innovations largely push new measurement requirement...

Self-heating has already been proven to be one of the key sources to memory effects in RF power amplifiers (PAs). However, mechanisms behind the generation of memory effects, as caused by self-heating have not been well documented. On basis of transistor physical properties this paper proposes a simple electro-thermal model and shows how self-heati...

This paper proposes an analytical model describing the generation of switching current noise in CMOS substrates. The model eliminates the need for SPICE simulations in existing methods by conducting a transient analysis on a generic CMOS inverter and approximating the switching current waveform using a Modified Raised Cosine (MORAC) equation. The p...

This paper presents a compact model for P+ guard rings in lightly doped CMOS substrates featuring a P-well layer. Simple expressions for the impedances in the model are derived based on a conformal mapping approach. The model can be used to predict the noise suppression performance of P+ guard rings in terms of S-parameters, which is useful for sub...

This paper presents a dual-mode ultra-wideband platform for wireless Remote Patient Monitoring (RPM). Existing RPM solutions are typically based on two different hardware platforms; one responsible for medical-data monitoring and one to handle data transmission. The proposed RPM topology is based on a single hardware platform, but it is capable of...

This paper presents a deembedding method that introduces the least square error algorithm as a means to retrieve the static nonlinearities of the dispersive output of power amplifiers excited by wideband modulated signals. The characteristics of static nonlinearities are expressed as polynomials and the coefficients are extracted from measured data...

The last chapter of this first part of the book, chapter seven, is devoted to Modeling of Substrate Noise and Mitigation Schemes for Ultrawideband (UWB) systems, and is written by Ming Shen, Jan H. Mikkelsen, and Torben Larsen from Aalborg University, Denmark. In highly integrated mixed-mode designs, digital switching noise is an ever-present probl...

Due to overlapping frequency bands, IEEE 802.11a WLAN and Ultra Wide-Band systems potentially suffer from mutual interference problems. This paper proposes a method for inserting frequency notches into the IR-UWB power spectrum to ensure compatibility with WLAN systems. In contrast to conventional approaches where complicated waveform equations are...

A new reconfigurable bandpass sigma–delta modulator (BPSDM) structure is proposed for low-IF multi-mode wireless systems. The proposed modulator can be reconfigured to operate in different signal bandwidths and at different signal-to-noise ratios by rearranging and optimizing the order of the noise transfer function of the loop while still maintain...

Compact modeling of P+ contact resistances is important for characterization of substrate noise coupling in mixed-signal System on Chips (SoCs). Existing contact resistance models can handle uniformly doped bulk or epitaxial substrates. However, compact contact resistance models feasible for modern lightly-doped CMOS processes with P-well layers ar...

This paper presents a compact two-stage ultra-wideband low-noise amplifier (LNA). A common-gate topology is adopted for the input stage to achieve wideband input matching, while a cascode stage is used as the second stage to provide power gain at high frequencies. A low power consumption and a small chip area are obtained by optimizing the performa...

This article presents a novel ultra-wideband bandpass filter with controllable notched bands, compact size, and relaxed fabrication requirements.Its implementation is based on a rectangular slot ring resonator with an embedded S-shaped slotline. The behavior of the rectangular slot ring resonator is characterized and subsequently adopted to build t...

A 1-5 GHz ultra-wideband CMOS low-noise amplifier (LNA) is presented. A common-gate topology is adopted for the input stage to achieve wideband input matching, while a cascode stage is used as the second stage to provide power gain at high frequencies. By using two inductors in the LNA, a small chip area is obtained. The LNA has been fabricated in...

Chapter 4 described the design and selection of the short range communication air interfaces tailored to Personal Networks application. These air interfaces consist of a low data rate (LDR) FM-UWB system and a high data rate (HDR) MC-SS system. The present chapter focuses on the hardware and software design and implementation that was carried out t...

This paper presents a measurement fixture suitable for measuring substrate carried noise for lightly doped substrates within the UWB frequency band. Signals coupling through the substrate are usually fairly weak and special precautions are taken to avoid any distortions that may be caused by the test fixture. The proposed measurement fixture is bas...

A measurement method for characterizing the substrate noise over the ultra-wideband (UWB) frequency band in UWB systems implemented using lightly doped CMOS processes is presented. The measurement structure in this method is based on modified ground-signal-ground (GSG) pads. In addition, the effects of the distance-based substrate resistance and th...

This paper describes the design and implementation of a fully differential RF front-end chipset for a low data rate FM-UWB based P-PAN receiver. The chipset includes an ultra-wideband LNA and a wideband RF demodulator. A 0.18 mum standard CMOS RF process is chosen as the technology vehicle. Measurement and demodulation function verification are pre...

This work presents an on-chip ground separation technique for power amplifiers. The ground separation technique is based on separating the grounds of the amplifier stages on the chip and thus any parasitic feedback paths are removed. Simulation and experimental results show that the technique makes the amplifier less sensitive to bondwire inductanc...

Traditionally, transceivers for wireless communication have to be carefully optimized for a given implementation technology in order to meet design targets. This compromises scalability and analog circuits therefore have to be redesigned when a design is to migrate between technology nodes. The added cost from redesign is not acceptable for low cos...

In this paper a fully differential implementation of a delay-line RF demodulator for FM-UWB based P-PAN receivers is presented and discussed. The implementation makes use of a dedicated circuit to remove possible phase imbalance in the differential signal pair. Without this correction demodulation performance is seriously affected. Detailed transis...

The polar transmitter is an attractive architectural solution for high-efficiency multi-mode handset applications. For the polar transmitter the design of a wide-band phase modulator is a challenging task especially for WCDMA signals. In this work the WCDMA signal is analyzed and based on this a method for solving the frequency jump problem is prop...

A 0.18 mum CMOS low power ring VCO for 3-5 GHz FM-UWB system applications is presented. In order to achieve a 1 GHz ultra-wide tuning range while retaining a low power consumption the conventional ring configuration is modified. A detailed analysis of the proposed VCO configuration is presented in terms of oscillating frequency, control performance...

This paper presents a two-stage quad-band CMOS RF power amplifier. The power amplifier is fabricated in a 0.25 mum CMOS process. The measured 1-dB compression point between 800 and 900 MHz is 15 dBm plusmn 0.2 dB with maximum 18% PAE, and between 1800 and 1900MHz is 17.5dBm plusmn 0.7dB with maximum 17% PAE. The measured gains in the two bands are...

A low power RF multiplier with ultra-wide signal response band is presented for ultra-wide band system applications such as an UWB demodulator (FM-UWB) or RF-correlator (impulse-radio). The principle of operation and the bandwidth theory is presented and discussed. The practical circuit is implemented using a 0.25μm CMOS process from UMC. The test...

This paper investigates a Q-enhanced LC resonator implemented with a Q-enhancement circuit based on both active and reactive components. An analytical expression is presented for the Q-enhancement circuit and simulations are compared with measurements on a differential Q-enhanced LC tank operating at 1779–1870 MHz. Sensitive circuits and inaccurate...

In this paper a single stage broadband CMOS RF power amplifier is presented. The power amplifier is fabricated in a 0.25μm CMOS process. Measurements with a 2.5 V supply voltage show an output power of 18.5 dBm with an associated PAE of 16% at the 1-dB compression point. The measured gain is 5.1 ± 0.5 dB from 1.65 to 2 GHz. Simulated and measured r...

Cellular multihop networks have the potential to decrease power consumption, increase coverage and/or enable higher data rates. We propose using in-band transmissions for the connection between a fixed repeating device and the cellular base station. A user connected via the repeater use one frequency band (fq2) for the communication to the repeater...

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This paper presents a differential Q-enhancement circuit implemented in a standard 5 metal layer, 0.25 μm CMOS process. A differential conductance of -2.8 mS is obtained at 2 GHz. This allows the circuit to compensate for a resistance of approximately 360 Ω. The differential reactance at this frequency is equivalent to 1 pF. An analytical expressio...

The coupling effects between two adjacent co-planar spiral inductors are characterized in two cases, one where no guard structure is used and one where simple guard-rings are used. In addition, the effect of guard-rings is evaluated at different distances (190 μm to 1090 μm) between inductors. The model traditionally used to predict this crosstalk...

The coupling effects between two adjacent coplanar spiral inductors are characterized for two cases, one where no guard structure is used and one where simple guard-rings are used. In addition, the effect of guard-rings is evaluated at different distances (190 μm to 1090 μm) between inductors. Measuring low levels of crosstalk is difficult, and in...

In this paper the design of a 2 GHz direct-downconversion mixer for a UTRA/FDD receiver is presented. The mixer is implemented using a standard low-cost 0.25 m, single-poly, six-metal CMOS process. An on-chip passive balun is used to generate a balanced RF input signal. In-house optimized device models are used for both active and passive component...

Unified RF requirements are derived for an UMTS Terrestrial RadioAccess/Frequency Division Duplex (UTRA/FDD) compliant mobile transceiver. Aset of transceiver requirements are proposed with consideration to systemissues including duplex aspects. From these design-compatible requirements areproposed for each functional block in the transceiver.

The first standardization phase for upcoming third-generation (3G) wireless communications is coming to an end. As is typical for standardization work, sufficient analog performance has been assumed and predominant emphasis has been placed on modulation and coding. However, recent revisions to the standardization document for the European wideband...

This paper presents a feasibility study of DC offset filtering for direct-conversion UTRA-FDD/WCDMA receivers. Spectral characteristics and properties of continuous transmission facilitate the use of simple high-pass filtering and this method is evaluated in the paper. Design equations for DC offset power to down-converted signal power ratio are pr...

This technical report documents a MATLAB toolbox -- GSMsim -- developed as part of a research effort on CMOS front-end RF-IC design. GSMsim provides a mean for evaluating the performance of both transmitter and receiver front-ends in a GSM system. The performance evaluation is of the Monte-Carlo type, and is based on a BER measure calculated by com...

This paper analyses two front-end receiver architectures intended for GSM900 use; (i) A direct-conversion receiver, and (ii) a low-IF receiver using a poly-phase filter. The aim is to determine the circuit performance required for GSM operation and to compare this to current state-of-the-art CMOS performance. The analysis shows that direct-conversi...

Recent advances in complementary-metal-oxide-semiconductor (CMOS) technology are expected to make it a viable option for RF designs into the 2-GHz range. This may make CMOS a strong contender for implementing transceivers in the International Telecommunications Union's (ITUs) proposed IMT-2000 global wireless system. Among the advantages promised b...

This paper addresses some of the architectural limitations and concerns in the devel-opment of CMOS high frequency front-ends for wireless communication applications. Dif-ferent architectures are evaluated as to how well their characteristics suite an all CMOS integrated solution. Also, the comparison aims at important parameters such as low cost,...

The need of high linearity is one of the principal drivers in the design of power amplifiers (PA) for new generation applications. Linear amplification is needed when the signals contain both amplitude and the phase modulation like QAM, QPSK, or OFDM. The other important issue in PAs is efficiency because the battery is one of the main components t...