P. Alinikula

Miniaturized artificial-transmission-line monolithic millimeter-wave frequency doubler

Millimeter-wave signals are typically generated by frequency multiplication in modern single-chip or multichip module (MCM) systems. Consequently, the multiplication efficiency, spurious rejection, and size of the frequency multiplier ultimately limit the integration level and cost of these systems. This paper points to the size reduction of millimeter-wave frequency doublers by evaluating artificial transmission lines (ATLs) as a means to minimize the size of the low-impedance shunt stubs. As a result, we developed a 40-GHz frequency doubler, which used only 0.6-mm/sup 2/ area on a monolithic microwave integrated circuit. Despite the area minimization, the doubler exhibited state-of-the-art conversion loss of 1 dB over 10% bandwidth and rejected the fundamental frequency signal by more than 20 dB over 25% bandwidth. Reported herein is the novel simulation of the frequency doubler with active harmonic loads. Included in this paper are theoretical evaluation and simulation of ATLs with models for lumped components and verification of the results by electromagnetic simulation. Due to the high efficiency, low area requirement, and over 20-dB rejection of the fundamental signal, this miniaturized ATL frequency doubler can be used as a building block in the generation of local-oscillator signals in single-chip and MCM millimeter-wave systems.

Active inductors for GaAs and bipolar technologies

Integrated high performance gallium arsenide and silicon active inductor configurations for microwave frequencies are examined in this article. The existing topologies are considered and a new aspect of comparing the performance of different topologies based on a more complete analysis is utilised. Drawbacks of GaAs technology in this particular case are recognised, while benefits attained by using bipolar technology are presented. A theoretical basis for designing bipolar inductors is examined. On the basis of these studies a new method for raising the Q-factor of an active inductor is found and applied to two novel GaAs Q-enhanced active inductors. New applications for active high-Q resonators are found and their realisation aspects are considered. Integrated test circuits have been designed, and the simulated and experimental results are presented.

Q-enhancing technique for high speed active inductors

Integrated active inductor configurations for RF frequencies are examined in this paper. A new aspect of comparing the performance of different topologies is used, and consequent differences between technologies are recognised. On the basis of these studies a new method for raising the Q-factor is presented and its applications considered.<<ETX>>

Monolithic active resonators for wireless applications

In this paper new tunable, monolithic active resonator topologies are presented. The circuits, based on the advances in GaAs MMIC active inductors, show stable, high-Q performance with large tunability and compact layout. The simulated results exceed significantly the properties of conventional varactor-tuned circuits. The new circuits are applied to active filters and proposed active resonator oscillators (ARO), which show great potential for wireless applications at the 2 GHz band.<<ETX>>

Low phase noise signal generation circuits for 60 GHz wireless broadband system

Demand for large capacity and low installation costs explains the extensive use of millimeter wave frequencies in digital wireless broadband communications. In digital wireless systems, the achievable bit error rate is strongly dependent on low phase noise in millimeter wave signal sources. The low phase noise can be achieved with frequency multiplication of high performance microwave oscillators. This study aims to reduce the size of millimeter wave frequency doublers by evaluating the spiral transmission line transformer as a means to minimize the size of the balun. As a result we developed a millimeter wave frequency doubler, which used only 0.3 mm/sup 2/ area on MMIC. We also present theoretical evaluation and simulation of these novel balanced frequency doublers. Furthermore, a 60 GHz frequency doubler was designed to demonstrate the frequency doublers in a millimeter wave signal source with ultra low phase noise.

Monolithic Artificial Transmission Line Balanced Frequency Doublers

Artificial transmission lines, realized using standard passive components of the foundry library, were utilized to design 180-degree baluns for millimetre wave frequency doublers. Monolithic integration of the complete doubler was achieved on extremely small chip area, 0.6mm2. However, the performance of the frequency doubler was not sacrificed, since the operating frequency bandwidth was 30 %. These results show the suitability of this new technique for integration of several of the functions of a transmit/receive unit economically on a very small area on chip.

Millimetre Wave Signal Generation Using Monolithic HEMTTechnologies

We have designed, processed and tested monolithic 40GHzfrequency doublers and amplifiers using enhancement and depletionHEMT processes. The passive parts included microstrip, coplanarwaveguide and lumped component circuits. The on-chip measuredoutput power of frequency doublers at 40GHz was +2dBm and the conversion loss was 2–;5 dB. The EHEMT doublersoperated at low input power level from a single DC supply andthe CPW passive parts enabled economical design. The integratedsystem of depletion PHEMT doubler and amplifier chips enclosedin hermetic packages delivered +10 dBm output powerat 38GHz frequency band. This is the first time that the applicationof enhancement mode HEMTs in frequency doublers is reported andcompared to the performance with depletion mode HEMTs. We haveproven that EHEMT and DHEMT frequency multiplier circuits areefficient solutions for local oscillator use in modern millimetrewave systems.

A Monolithic Temperature Compensated 1.6 GHZ VCO

A temperature compensated fully integrated 1.6 GHz harmonic VCO with GaAs E/D-MESFET technology has been designed for telecommunication applications. The circuit has a measured tuning range of over 400 MHz and it shows a good tuning linearity in the range of 1600 - 1700 MHz. With the proposed temperature compensation scheme the measured frequency drift is reduced from 36 MHz to less than 8 MHz in the temperature range of ¿20 ... +70°C.

Integrated BiCMOS IF-modules for mobile telecommunication applications

Integrated IF-modules for mobile phone applications have been designed with-1.2 um BiCMOS technology. These modules consist of the transmitter, receiver and temperature independent gain-adjustment circuits. The 80 dB dynamic range over 50 MHz bandwidth of both the transmitter and receiver is achieved with the current stearing gain control amplifier. The gain control amplifier has an 80 dB dynamic range which is achieved with the current stearing gain control amplifier. The gain control is linear within +/- 0.5 dB and temperature compensated. The temperature compensation is performed in current mode. The dynamic range requirement is especially challenging for the logarithmic amplifier in the peak detector, in which a current feedback amplifier has been applied. These modules are intended to be combined on a single chip with the realised baseband filtering circuit. The total area of the circuits is 6 mm2 and the power consumption is 60 mA.<<ETX>>

Local Oscillator Generation Circuit for Direct Conversion Transmitter

In this paper a fully monolithic on-chip local oscillator signal generation circuit is presented for eliminating the negative effect of coupling between bond-wires, package pins and output and input lines of the power amplifier output to the local oscillator input for direct conversion transmitters. The proposed circuit generates the local oscillator signal at frequencies 1710–1785 GHz which is harmonically uncorrelated from two input signals at 464 MHz and 1792–2088 MHz. The required building blocks are a frequency divider, a mixer and an active band-pass filter. Fully monolithic high frequency band-pass filters have not been available until recently, and the designed circuit is in fact one of the first applications reported for MMIC active filters in cellular phones. The circuit is designed with a 0.5 μm GaAs MESFET technology and the performance is verified with on-chip measurements.