Johann-Friedrich Luy

Silicon-Based Millimeter-Wave Devices

1. Fundamentals.- 1.1 Silicon as the Base Material for MMICs.- 1.2 Linear Passive Planar Millimeter Wave Circuits on Silicon.- 1.2.1 Wave Propagation in Planar Structures.- 1.2.2 Planar Transmission Lines.- 1.2.3 Planar Transmission-Line Discontinuities.- 1.2.4 Planar Resonators.- 1.3 Planar Millimeter-Wave Antennas on Silicon.- 1.3.1 Antenna Elements.- 1.3.1 Antenna Arrays.- 1.4 Planar Millimeter-Wave Circuits Containing Active and Nonlinear Elements.- 1.5 Appendix: Closed-Form Expressions for Transmission-Line Characteristics.- References.- 2. Transit-Time Devices.- 2.1 Principles of Transit-Time-Induced Negative Resistance.- 2.2 Injection Mechanisms.- 2.2.1 Impact Ionisation - IMPATT Diode.- 2.2.2 Thermionic Emission - BARITT Diode.- 2.2.3 Tunnel Injection.- 2.2.4 The Misawa Mode.- 2.3 Numerical Large-Signal Simulations.- 2.4 Skin Effect.- 2.5 Thermal Properties.- 2.5.1 Integrated Transit-Time Devices.- 2.5.2 Diamond Heat Sinks.- 2.5.3 Ring Diodes.- 2.5.4 Transient Thermal Resistance.- 2.5.5 Measurement of the Thermal Resistance.- 2.6 Design Constraints.- 2.7 Technology.- 2.7.1 Material Growth.- 2.7.2 Contacts.- 2.7.3 Handling Techniques.- 2.7.4 Packaging.- 2.8 Performance.- 2.8.1 Power.- 2.8.2 Efficiency.- 2.8.3 Noise.- 2.9 New Transit-Time Device Concepts.- References.- 3. Schottky Contacts on Silicon.- 3.1 Schottky-Barrier Models.- 3.1.1 The Schottky Mott Model.- 3.1.2 The Space Charge Region.- 3.1.3 Bardeens Model.- 3.1.4 Linear Models.- 3.1.5 Barrier Height Correlations.- 3.1.6 Advanced Models: Charge Transfer Across the Interface.- 3.2 Epitaxial Diodes on Si.- 3.2.1 Single-Crystalline Schottky Contacts.- 3.2.2 Other Orientational Dependences.- 3.2.3 CaSi2 and Ag.- 3.2.4 Polycrystalline Epitaxial Contacts on Si.- 3.2.5 Unconventional Metals with Small Lattice Mismatch to Si.- 3.2.6 Summary.- 3.3 Electrical Transport Properties.- 3.3.1 Emission Over the Barrier.- 3.3.2 Tunneling Through the Barrier.- 3.3.3 Generation Recombination in the Space Charge Region.- 3.3.4 Minority Carrier Injection.- 3.3.5 Inhomogeneities in Schottky Contacts.- 3.3.6 Noise Properties.- 3.3.7 Microwave Properties.- 3.4 Schottky-Barrier Measurements.- 3.4.1 Current-Voltage Curves.- 3.4.2 Capacitance Measurements.- 3.4.3 Internal Photoemission (Photoresponse).- 3.4.4 External Photoemission.- 3.4.5 Results for Polycrystalline Contacts.- 3.5 Conclusions.- References.- 4. SiGe Heterojunction Bipolar Transistors.- 4.1 Operation Principle of Homojunction and Heterojunction Bipolar Transistors.- 4.1.1 The Bipolar Junction Transistor and Its Physical Limits.- 4.1.2 The Heterojunction Bipolar Transistor.- 4.1.3 The Si/Ge Material System.- 4.2 Design of SiGe HBT Layers.- 4.2.1 Emitter Design.- 4.2.2 Base Design.- 4.2.3 Collector Design.- 4.3 Fabrication Technologies and Device Performance.- 4.4 Applications of SiGe HBTs.- 4.5 Conclusion.- References.- 5. Silicon Millimeter-Wave Integrated Circuits.- 5.1 Silicon as the Substrate Material.- 5.1.1 Silicon-Substrate Waveguide Parameters.- 5.1.2 Surface Waves.- 5.2 Millimeter-Wave Sources for SIMMWICs.- 5.2.1 IMPATT Oscillator.- 5.2.2 Varactor-Tuned Oscillator.- 5.2.3 HBT Oscillator.- 5.3 SIMMWIC Transmitter.- 5.3.1 Thermal Limitation of Monolithic IMPATT Diodes.- 5.3.2 Coplanar Slot-Line Transmitter.- 5.4 SIMMWIC Receiver.- 5.4.1 Microstrip Receiver.- 5.4.2 Coplanar Slot-Line Receiver.- 5.4.3 Resonant Tunneling Rectenna.- 5.5 SIMMWIC Switch.- References.- 6. Self-Mixing Oscillators.- 6.1 Principle of Operation.- 6.2 Linear Disturbance Theory.- 6.2.1 Model for the Self-mixing Oscillator.- 6.2.2 Conversion-Gain Factors.- 6.2.3 Simplified Device Model.- 6.3 Matrix Formulation of Conversion Gain.- 6.3.1 Conversion Matrix.- 6.3.2 Conversion Gain.- 6.4 Noise in Self-Mixing Oscillators.- 6.4.1 RF Noise.- 6.4.2 Low Frequency Noise.- 6.5 Numerical Simulations.- 6.6 Measuring Techniques and Experimental Results.- 6.6.1 Measuring Set-up.- 6.6.2 Experimental Results of a Si-IMPATT Device in the V-band.- References.- 7. Silicon Millimeter-Wave Integrated Circuit Technology.- 7.1 Technological Requirements for a Millimeter-Wave Substrate.- 7.1.1 Historical Background of SIMMWIC Technology.- 7.1.2 Characterization of High-Resistive Silicon Substrates.- 7.1.3 Behaviour of High-Resistive Silicon Substrates During Fabrication Processes.- 7.2 Basic Technologies.- 7.2.1 Buried Layers.- 7.2.2 Epitaxial Growth.- 7.2.3 Lithography.- 7.2.4 Pattern Transfer.- 7.2.5 Metallization and Air Bridge Technology.- 7.3 Fabrication Process and Monolithic Integration of Two-Terminal Devices.- 7.3.1 Fabrication Process of Coplanar Schottky-Barrier Diodes.- 7.3.2 Fabrication Process of Monolithically Integrated Transit-Time Diodes.- 7.3.3 Fabrication Process of Lateral PIN Diodes.- 7.4 Fabrication Process of Three-Terminal Devices.- 7.4.1 Bipolar Transistors.- 7.4.2 Hetero Bipolar Transistors for SIMMWICs.- 7.5 Summary and Prospects.- References.- 8. Future Devices.- 8.1 Physics and Applications of Si/SiGe, Double-Barrier Structures.- 8.1.1 Band Structure of Si/SiGe.- 8.1.2 Tunneling Current Calculation.- 8.1.3 The Quantum-Mechanical Concept of Electromagnetic Oscillations from Resonant-Tunneling Double Barriers.- 8.1.4 Calculation of fmax for n-type Si/SiGe Tunneling Diodes.- 8.1.5 Equivalent-Circuit Analysis of Oscillation Frequency and Output Power from an n-type Si/SiGe Double-Barrier Diode.- 8.1.6 Millimeter-Wave Detection by Si/SiGe Double Barriers.- 8.2 The Si/SiGe Quantum Barrier Varactor Diode.- 8.3 Field-Effect Devices: Si/SiGe MODFET and MOST, ?-Doped Si FET.- 8.3.1 dc and HF Modeling.- 8.3.2 Modeling Results and Comparison with Si n- and p-MOSTs.- 8.3.3 Experimental Results.- 8.3.4 Processing Steps: Growth and Post Processing.- Appendix 8.A The Effective-Mass Approximation.- Appendix 8.B Maximum Oscillation Frequency and Power Generation.- References.- 9. Future Applications.- 9.1 Sensor Applications.- 9.1.1 Measurement Principles.- 9.1.2 Radiometric Sensors.- 9.1.3 cw Radar Sensors.- 9.1.4 Frequency Modulated Radar Sensors.- 9.1.5 Pulse-Modulated Radars.- 9.2 Communication Applications.- 9.2.1 General Considerations.- 9.2.2 Identification Card Systems.- 9.2.3 Short-Range Data Transmission.- 9.2.4 Information Systems.- 9.2.5 Millimeter-Wave Data Bus.- 9.3 System Requirements.- 9.3.1 General System Aspects.- 9.3.2 Frequency Stability.- 9.3.3 Environmental Conditions.- 9.3.4 Packaging.- References.

Configurable RF receiver architectures

In the heterogeneous world of communication and radar systems, a steadily increasing number of technical approaches for different applications are observed. A new application on the horizon is the transmission of very high data rate streams (> 500 Mb/s) during a short time interval between moving clients. Such applications may be applicable to future intelligent traffic control systems based on R.D. Kuhne (2002) and will require the support of different standards for communication and radio location services. The high data rates require high bandwidths, which become available at millimeter wave frequencies. From an engineering point of view, we may not be unsatisfied with a growing number of tasks, however, economic aspects are forcing us to search for unified solutions that do not require reengineering for every new or modified application. Therefore, the goal is to shift functionality from hardware to software. For example, channel selection and demodulation can be implemented as software codes and are no longer hardware realizations. These software-defined radios (SDRs), which compute classical receiver functions, can be reconfigurable. Therefore, the need for hardware solutions that can handle several standards and related software implementations arises. It is the purpose of this article to compare two very promising solutions (sampling and six-port) with respect to their suitability in the millimeter-wave range and to discuss some related research aspects.

3D silicon micromachined RF resonators

Passive components with high quality factor are required for many applications, e.g., filters. In the field of micromachining, this is commonly achieved by using multiple-wafer structures. An alternative technique is presented here together with design and measurement data, which is based on MEMS technology and yields single-wafer resonators thus reducing costs. Cavity resonators with the Si being partly removed show quality factors Q beyond 360.

RF-MEMS switching concepts for high power applications

RF MEMS switches for power applications are discussed in this paper. Mechanical and electromagnetic simulations of a new switch type for power applications are presented, and fabrication aspects are discussed.

Toggle-switch - a new type of RF MEMS switch for power applications

A new type of RF MEMS switch for power applications using a push-pull concept is described. The switching element consist of a cantilever which is fixed by a suspension spring to the ground of the coplanar lines. The switching voltages are 30 V to close and 35 V to open. The switches exhibit low loss (<0.2 dB at 27 GHz) with good isolation (20 dB at 27 GHz).

Silicon Micromachined CPW Transmission Lines

MEMS technology with its three-dimensional (3D) treatment of substrates allows realization of CPWs with lower attenuation. This is achieved by removing the substrate material in the gap between signal and ground metalizations of the CPW transmission lines. A series of different removing/underetching schemes was investigated and processed and compared with common CPW lines. This paper explains the idea as well as the micromachining process steps used. Lowest measured attenuation was 0.081 dB/mm at 40 GHz for CPW lines with ground to ground spacing of 300 ¿m and substrate removal of 60 ¿m in depth. This corresponds to an improvement in attenuation of more than 20% compared to common CPW lines.

A multifunctional antenna for terrestrial and satellite radio applications

A multifunctional antenna is presented for the application in terrestrial radio services like GSM 900 MHz, DCS 1800 MHz as well as for satellite radio services like GPS 1575 MHz. At the terrestrial frequency bands GSM 900 MHz and DCS 1800 MHz the antenna exhibits omnidirectional radiation characteristics in horizontal plane for vertical polarized waves. At the frequency bands of the satellite radio services like GPS and Globalstar the antenna exhibits a radiation characteristic with a vertical main lobe and a circular polarized field.

An extremely broadband software configuration six-port receiver platform

A software configurable receiver front-end based on six-port technology for a frequency range from 2 GHz to 20 GHz is presented. Its discriminator circuit is composed of coaxially connected, and commercially available passive elements. Simulation and measurement results of quadrature phase shift keying (QPSK) demodulation tests at carrier frequencies between 2 GHz and 20 GHz are shown. Without the use of hardware filters and amplifiers data rates up to 1 MBit/s can be demonstrated. The achieved low bit error rate (BER) proves the capability of this new concept for high bit rate wireless data links. For demodulation, a new packet based real-time calibration method was applied. Due to its inherent broad band properties, the proposed front-end is especially qualified for the realisation of multistandard, reconfigurable receiver platforms. An introduction to emerging six-port applications will be given. The functional principle of the six-port receiver including the theoretical background are explained. Simulation and measurement results are discussed and possible improvements will be pointed out.

Implementation of a smart antenna system with an improved NCMA algorithm

This paper presents the possibility of using adaptive algorithms for digital beamforming purposes. A normalized constant modulus algorithm (NCMA) is implemented in a standard FPGA. In this way, a simple and non-hardware-intensive, smart antenna system in combination with a software-defined radio (SDR) has been realized for mobile FM reception. A new kind of algorithm initialization, leads to an improvement in startup behavior. The quality in signal separation makes the NCMA algorithm also suitable for MIMO purposes. The NCMA algorithm increases the reception quality for mobile communication systems dramatically.

Silicon-based millimeter-wave integrated circuits

Abstract Microwaves at frequencies above 30 GHz (millimeter waves), which offer several advantages, are mainly used at present for military applications. A broad civil market will be opened if a cost-effective planar integration can be achieved. The suitability of high resistivity silicon for planar millimeter-wave integration is described. To produce silicon monolithic millimeter-wave integrated circuits (SIMMWICs) the device structures are grown by molecular beam epitaxy on high-resistivity silicon substrate. Discrete impact avalanche transit time (IMPATT) and Schottky diodes fabricated from this material show excellent performances at 100 GHz: they have more than 1 W oscillator output power and a detector tangential signal sensitivity of − 52 dB m at around 90 GHz. For specific applications the device characteristics can be influenced by the introduction of SiGe heterojunctions. The MITATT (mixed tunneling avalanche transit time) oscillator and the resonant tunneling detector are given as examples. Hybrid integrated transmitters, voltage-controlled oscillators, and mixers can be fabricated on high resistivity silicon. The transmitter oscillator with a double-drift IMPATT diode as the active element emits a maximum continuous wave output power of 200 mW at 73 GHz. The advantages of the coplanar waveguide are pointed out and monolithic integrated oscillators and detectors are demonstrated. The chip with a coplanar Schottky diode as the detector element and a microstrip antenna with 36 radiating elements shows a sensitivity of 65 microV microW −1 cm −2 . The first applications of the described circuits for traffic surveillance are described and discussed.