This paper provides an overview on the main additive manufacturing/3D printing technologies suitable for many satellite applications and, in particular, radio-frequency components. In fact, nowadays they have become capable of producing complex net-shaped or nearly net-shaped parts in materials that can be directly used as functional parts, including polymers, metals, ceramics, and composites. These technologies represent the solution for low-volume, high-value, and highly complex parts and products.

Overview on Additive Manufacturing Technologies

This expanded and thoroughly revised edition of Thomas H. Lee's acclaimed guide to the design of gigahertz RF integrated circuits features a completely new chapter on the principles of wireless systems. The chapters on low-noise amplifiers, oscillators and phase noise have been significantly expanded as well. The chapter on architectures now contains several examples of complete chip designs that bring together all the various theoretical and practical elements involved in producing a prototype chip. First Edition Hb (1998): 0-521-63061-4 First Edition Pb (1998); 0-521-63922-0

The Design of CMOS Radio-Frequency Integrated Circuits: RF CIRCUITS THROUGH THE AGES

Phased-array radar is widely used in localizating non-cooperative targets, but the range and angle of targets cannot be directly estimated from its beamforming output due to an inherent range ambiguity, i.e., two-dimensional localization of non- cooperative targets cannot be obtained directly from conventional linear phased-array radar beamforming peaks. This paper proposes a simple range-angle localization of targets by uniform linear array (ULA) double-pulse frequency diverse array (FDA) radar. The FDA transmits two pulses with zero and non-zero frequency increments, respectively. The azimuth angle and slant range of targets are then estimated directly from the beamforming output peaks. This approach can be interpreted as detecting the targets in angle dimension and then localizing them in range dimension by properly choosing the frequency increment. Moreover, multiple FDA radars can work as netted radar networks, in which distinct frequency increments or orthogonal waveforms are employed. The localization performance is examined by analyzing the Cramer-Rao lower bound (CRLB) and numerical mean square error (MSE). The effectiveness is demonstrated by simulation results.

Range-Angle Localization of Targets by A Double-Pulse Frequency Diverse Array Radar

i»?Phased-array antennas are known for their capability to electronically steer a beam with high effectiveness, but beam steering is fixed in an angle for all range cells. This paper reviews frequency diverse array (FDA) antennas. Different from a phased array, an FDA uses a small frequency increment, as compared with the carrier frequency, across array elements. The use of a frequency increment generates an array factor that is a function of the angle, the time, and the range, allowing the FDA antenna to transmit the energy over the desired range and angle. In addition to analyzing FDA factor characteristics, this paper investigates FDA potential applications in range-dependent energy control and technical challenges in system implementation, with an aim to call for further investigations on the FDA.

Frequency Diverse Array Antenna: New Opportunities

Terahertz Beam Steering Technologies: From Phased Arrays to Field-Programmable Metasurfaces

A miniature non-uniform copper-air rectangular coaxial line with the inner conductor supported by periodic dielectric straps is demonstrated. The overall height of the line is 310mum with the outer conductor cross-section being 250mumtimes250mum. The measured loss is 0.22dB/cm at 26GHz, while the isolation between two parallel lines with a center-to-center separation of 700mum is better than 60dB. Several quasi-planar components are designed and fabricated on the same wafer, and presented here are a branch-line hybrid and a transmission line resonator. The through and coupled port transmissions for the hybrid at 26GHz are -3.25dB and -3.35dB respectively, with phase misbalance below 0.2deg. The transmission line resonator has an unloaded Q-factor of 110 at 25GHz

http://ecee.colorado.edu/microwave/docs/publications/2006/IMS-DFetal-June06-small.pdf

Modeling, Design, Fabrication, and Performance of Rectangular μ-Coaxial Lines and Components

This paper describes frequency scanning slot arrays operating from 130 to 180 GHz. The arrays are micro-fabricated using the PolyStrata sequential copper deposition process. Measured reflection coefficient and radiation patterns agree with HFSS full-wave simulations. The voltage standing wave ratio is less than 1.75:1 over the entire frequency range, and the measured scanning is 1.04°/ GHz from 130 to 150 GHz and 32.5° over the full frequency range. The measured gain is 15.5 dBi for a 10-element array at 150 GHz and 18.9 dBi for a 20-element array at 150 GHz with about 3 dB of variation over the scan range.

Micro-Fabricated 130–180 GHz Frequency Scanning Waveguide Arrays

This paper presents several micro-coaxial broadband 2 : 1 Wilkinson power dividers operating from 2 to 22 GHz, a 11 : 1 bandwidth. Circuits are fabricated on silicon with PolyStrata technology, and are implemented with 650 mum times 400 mum air-supported micro-coaxial lines. The measured isolation between the output ports is greater than 11 dB and the return loss at each port is more than 13 dB over the entire bandwidth. The footprints of these dividers can be miniaturized due to the high isolation between adjacent coaxial lines and their tight bend radius. For higher power handling, larger lines with a cross section of 1050 mum times 850 mum are also demonstrated. The effect of mismatch at the output ports is investigated in order to find the power loss in the resistors.

Broadband Micro-Coaxial Wilkinson Dividers

Air-filled copper Ka-band resonators with heights between 250-700 mum are demonstrated with measured unloaded Q factors between 440-829. The low-profile quasi-planar resonators are fabricated using a sequential metal deposition process. Miniaturization of up to 70% with respect to a TE101 quasi-planar resonator is accomplished by reducing the footprint of the resonator while maintaining the height. Finite-element simulations predict the measured resonant frequency within less than 1%. Due to fabrication imperfections, Q un is measured to be approximately 15% less than predicted. The resonators are compatible with air-filled rectangular microcoaxial feed lines fabricated in the same metal-deposition process.

$Ka$ -Band Miniaturized Quasi-Planar High- $Q$ Resonators

Miniature hybrid couplers are designed in an air-filled microfabricated rectangular coaxial line technology for operation near 36 GHz. The size of the couplers is less than 2.7 mm by 2.7 mm in area and 420 μm in height. Air-filled copper μ-coaxial cable provides less than 0.3 dB/cm loss at Ka-band. Coaxial-to-CPW probe transitions on the ports provide means to perform 4-port VNA measurements with an external SOLT calibration. After implementing a de-embedding procedure, measurements show return loss and isolation better than 20 dB, with output amplitudes of 3.2 dB±0.1 dB, and output phase differences of 90° ± 2.0° from 34.5 to 36.5 GHz. The return loss and isolation minima are shifted in frequency as compared to the optimal output amplitude and phase frequency. This frequency difference is 1.5 GHz near 36 GHz with this technology, however branch line couplers using branch-length and reactive tee-junction compensation methods are presented. The improvement is experimentally verified; the frequency differences are 0.5 and 0.2 GHz for the two compensated designs.

Kenneth Vanhille

Papers

Modeling, Design, Fabrication, and Performance of Rectangular μ-Coaxial Lines and Components

Micro-Fabricated 130–180 GHz Frequency Scanning Waveguide Arrays

Broadband Micro-Coaxial Wilkinson Dividers

$Ka$ -Band Miniaturized Quasi-Planar High- $Q$ Resonators

Balanced Low-Loss Ka-Band μ-Coaxial Hybrids