D. Rohde

Low-phase-noise millimeter-wave generation at 64 GHz and data transmission using optical sideband injection locking

The 60-GHz band is proposed for the radio link frequency in broad-band cellular systems. 140-155-Mb/s transmission experiments are reported with optically generated millimeter-waves at frequencies in the 60-GHz band. By applying the sideband injection locking technique, the remotely generated millimeter-wave signals depict quartz accuracy and low phase noise <-100 dBc/Hz at offset frequencies 21 MHz.

Photonic 60-GHz maximum directivity beam former for smart antennas in mobile broad-band communications

Experiments are described using a photonic beam former to control a 60-GHz smart antenna. The 60-GHz signals are generated by optical heterodyning the waves of two laser diodes. Beam forming is achieved by new photonic planar lightwave circuits in silica technology. The beam former enables individual weighting of the millimeter-wave signals feeding the antenna elements. The required weights for a desired field distribution are calculated using the maximum directivity beam-forming algorithm.

Experiments on DOA-estimation and beamforming for 60 GHz smart antennas

In this paper we present experimental results on direction of arrival (DOA) estimation and optical beamforming. In this first part of the paper we describe the experimental set-up for the antenna calibration and DOA estimation at 60 GHz. A pilot signal generator and an array receiver are implemented. The feasibility of the DOA estimation is evaluated for real conditions. The experimental results show that the array calibration works reliable and there is a good agreement between simulation and experiment in the DOA estimation. In the second part, we present the experimental results on beamforming, which is performed using optical millimeter-wave generation technique. The millimeter-wave signals are generated by heterodyning the signals of two lasers. Beamforming is accomplished by a newly developed SiO/sub 2//Si beamforming network, which enables individual control of amplitudes and phases of millimeter-wave signals feeding a planar 1/spl times/4 array antenna by means of the maximum directivity beamformer algorithm. Farfield measurements show good agreement between theory and experiment.

Balanced phase and polarization diversity coherent optical receiver

A balanced phase and polarization diversity receiver employing a compact bulk optical 90 degrees hybrid and a silicon bipolar multiplier IC is described. The compact bulk optical hybrid provides all required optical signals with well-defined phase relations in a single unit and is therefore a good solution of the problems associated with the complex structure of the optical part of the receiver. The multiplier IC has a dynamic range of at least 15 dB. It guarantees that variations of the signal power in the different detection branches of the receiver cause negligible degradation in both diversity operations. The receiver has been tested in a 565-Mb/s DPSK transmission system.<<ETX>>

Optical millimeter-wave generation and transmission technologies for mobile communications, an overview

The success of future broadband mobile cellular communication systems rely to a great extent on reliable, low-cost components and technological principles. Especially in pico-cell scenarios needing many base stations the radio-over fiber technology is required for transmitting and generating millimeter-wave signals. Several approaches at frequencies up to 60 GHz are reviewed. This paper briefly reviews systems with intensity modulation and direct detection but the main focus is on systems based on heterodyne techniques using single or multiple optical sources in the control station for generating a single millimeter-wave carrier or a complete optical frequency division multiplex for the conversion to the millimeter-wave domain.

Optical beam forming of MM-wave array antennas in a 60 GHz radio over fiber system

We report on new results of a novel silica based signal processor for optical beam forming in wireless communication smart antenna systems. Basic components and measurements of an envisaged 60 GHz transmission system are described.

Fiber-optic millimeter-wave generation at 64 GHz and spectral efficient data transmission for mobile communications

Summary form only given. The optical generation and transmission of millimeter-waves is promising for future cellular broadband mobile communication systems operating at frequencies up to 60 GHz. These systems comprise millimeter-wave components for the radio link between the mobile station (MS) and the base station (BS). Optical components are used in the BS and the control station (CS) for the broadband, low-loss connection and for generating millimeter-wave signals. The costs of the numerous BSs should be kept as low as possible. Therefore the generation and control of the millimeter-wave signals should be carried out remotely in the CS, thus obviating the need for millimeter-wave oscillators and modulators in the numerous BSs. In the experimental setup an optical transmitter contained two DFB lasers, depicted as signal laser (LDS), and as reference laser (LDR). Their optical output signals were heterodyned using an optic/millimeter-wave converter in the BS. The lasers were stabilized by sideband injection locking. The master laser (LDM) was modulated by a 3.2-GHz signal via its injection current. LDS and LDR were injection locked to -10th and +10th modulation sidebands.

Silica based beamformer for 60 GHz smart antennas

We report on first results of a novel silica based signal processor to be used for beamforming in smart antenna environments. An experiment with some components of an envisaged 60 GHz transmission system is described.

Photonic beam-forming for millimeter-wave mobile communications

Smart antennas are important for mobile broadband transmission systems. We present results of downlink and uplink beam-forming experiments and 155 Mbit/s data transmissions at 60 GHz and 40 GHz using a silica based photonic beam-former.