Ibrahim Haroun

Experimental Analysis of a 60 GHz Compact EC-CPW Branch-Line Coupler for mm-Wave CMOS Radios

A 60 GHz reduced-size branch-line coupler has been developed using elevated-center coplanar waveguide (EC-CPW) transmission lines. The coupler is fabricated in a 90 nm CMOS technology and has a chip area of 0.102 mm2. The measurements indicated an amplitude-imbalance of 0.7 dB and a phase difference of 88 degrees at 60 GHz, a return loss of greater than 15 dB at every port over the 60 GHz band (57-64 GHz), and an isolation better than 17 dB. A 73% size-reduction compared to a conventional CPW coupler design has been achieved using capacitively loaded high-impedance EC-CPW lines. The proposed coupler is well suited for the design of millimeter-wave (mmW) CMOS subsystems including: balanced amplifiers, vector modulators, and balanced mixers.

Compact 60-GHz IPD-Based Branch-Line Coupler for System-on-Package V-Band Radios

A compact 60-GHz band branch-line coupler using cpacitively loaded lower-ground coplanar-waveguide (LG-CPW) lines has been successfully demonstrated in a glass-substrate integrated passive device technology. The fabricated coupler has a size reduction of more than 83% compared to that of a conventional CPW branch-line coupler. The capacitive loading is achieved by utilizing the signal layer and the LG of the LG-CPW structure to form microstrip open-circuited stubs. The measured results show a phase error of less than 0.5° between the couplers output ports and an amplitude imbalance of less than 1.2 dB over the frequency band 57-64 GHz. The measurements also show that both the return loss and isolation are better than 25 dB at 60 GHz and better than 15 dB over the 57-64-GHz band. The proposed coupler is well suited for low-cost high-performance system-on-package V-band radio front ends for high data rate applications.

High-Performance, Compact Quasi-Elliptic Band Pass Filters for V-Band High Data Rate Radios

This paper presents a comparison of the design and implementation of V-band quasi-elliptic band pass filters suitable for system-on-package integration at millimetre-wave frequencies. Filters were designed and manufactured at low-temperature co-fired ceramic (LTCC) and alumina substrates. Filter circuits include the input/output coplanar waveguide to microstrip transitions as well as the microwave pads, used to facilitate measurement. Three four-pole filters incorporating half-wavelength resonators were implemented, two planar (on LTCC and alumina substrates) and one vertically stacked (on LTCC). In addition a six-pole filter was also implemented in alumina. The four-pole LTCC based filters have a measured insertion loss (IL) as low as 3.4 dB, fractional bandwidth (FBW(%) = BW-3 dB/Center Frequency) of 4.8% and return loss better than 10 dB. Total filter size is less than 1.1 × 0.74 mm. The alumina-based four-pole/six-pole filters exhibit a measured IL of 2.8/3.1 dB, FBW of 8.3%/12.6%, respectively. Both alumina filters exhibit a return loss better than 10 dB and with a corresponding filter layout footprint of less than 1.01 × 1.34 mm. A new figure-of-merit (HPFOM) is proposed and results from the filters proposed here clearly show they offer the best trade-off between performance and area (higher HPFOM).

Experimental characterization of EC-CPW transmission lines and passive components for 60-GHz CMOS radios

In this work, we propose the use of elevated center coplanar waveguide (EC-CPW) transmission lines in CMOS technology to alleviate the technology limitations of achieving extreme impedances with conventional CPW lines, particularly, high impedances. High impedance lines are required to facilitate the design of matching networks and to reduce the size of the passive components by utilizing capacitively loaded high-impedance lines. This paper presents the measured and simulated performance of these lines and their implementation in building a 60 GHz reduced-size 90° coupler. The couplers size is 0.102 mm2 and it is well suited for use in the design of radio front-ends of 60 GHz high data-rate wireless systems.

60-GHz rat-race coupler using LG-CPW transmission lines in IPD technology

A reduced size rat-race coupler is proposed and designed for operation in the 60-GHz band (57–64 GHz) and is implemented in a glass-substrate IPD (Integrated Passive Devices) technology. A size reduction of 75% compared to that of a conventional rat-race coupler has been achieved by using high impedance lower-ground coplanar waveguide (LG-CPW) transmission lines that are loaded at their ends with microstrip open-circuited stubs. The experimental results of the coupler exhibited an amplitude imbalance of less than 0.5 dB and a phase variation of 5-degrees over the 57–64 GHz band. The achieved measured return loss is greater than 15 dB and the isolation is greater than 24 dB over the 57–64 GHz band. The measured results confirm the potential of the proposed rat- race coupler for use in low-cost, high performance radio front ends for 60-GHz band system-on-package radio-over-fiber communication systems.

Multi-band 700MHz/ 2.4GHz/ 60GHz RF front-end for radio-over-fiber base stations

A radio-over-fiber RF front end is being developed for multi-band operation covering 700 MHz, 2.4 GHz and 60 GHz. The RF front-end of the system was implemented on FR4 substrate and the optical part of the system was implemented using commercial components. Initially, a 700 MHz system based on 2.4GHz WLAN was demonstrated and achieved a 6-Mbps data rate transmission over a 4-km optical link and a 2.5-meter wireless link with transmit power of only 1mW at the base station. Meanwhile, various blocks for the 60 GHz band require further development, and an example of our efforts is a low noise amplifier (LNA) that was designed and developed in CMOS technology, the amplifier achieved noise figure less than 5 dB and a gain of 10 dB over 8 GHz bandwidth covering the frequency range of 50–58GHz and will be presented here. These developed components are well suited for RF front-ends in radio-over-fiber (RoF) communication systems.

A reduced-size, low-loss 57–86 GHz IPD-based power divider using loaded modified CPW transmission lines

A reduced-size, low-cost, low insertion loss power divider operating over a very broad bandwidth from 57-86GHz is designed, manufactured, tested, and presented in this paper. The proposed design is fabricated in a glass-substrate IPD (integrated passive device) technology and has a chip area of 0.435×0.36 mm2. A size-reduction of 33% compared to a conventional microstrip Wilkinson power divider has been achieved by using high-impedance modified coplanar waveguide (M-CPW) transmission lines, which are loaded at their ends with microstrip open-circuited stubs. The measured results showed an insertion loss of less than 0.5 dB over a frequency range of 50-67 GHz; the EM simulation results showed an insertion of less than 1.4 dB loss over a frequency range of 50-90 GHz. The proposed design is well suited for low-cost system-in-package (SiP) radio front-ends for multiband 60/70/80-GHz high data rate wireless communications systems.

A compact 24–26 GHz IPD-based 4×4 Butler matrix for beam forming antenna systems

A compact 24-26 GHz low loss 4×4 Butler matrix is implemented in an IPD (integrated passive device) technology and presented in this paper. A modified coplanar waveguide (M-CPW) branch line coupler is utilized as the core element of the Butler matrix. The proposed Butler matrix occupies a chip area of 2.2 × 1.9 mm2 (excluding the I/O test pads). The measured results showed output relative phase errors of less than 5% over a frequency range of 26-29 GHz and less than 13% over 24-25 GHz, and output amplitude imbalances of less than 1.3 dB over a frequency range of 24-27 GHz. The proposed Butler matrix is well suited for use in microwave low-cost, high performance beam forming wireless communications systems.

Integrated Passive Device based RF circuit design for low-cost System-in-Package transceivers

This article presents and discusses the design of RF circuits using Integrated Passive Devices (IPDs) technology appropriate for the development of low-cost and high performance System-in-Package (SiP) wireless transceivers. Two examples, a 6-GHz voltage-controlled oscillator (VCO) and a 60-GHz 90° coupler are introduced to demonstrate the implementation of RF circuit design using an IPD process. Experimental results of the VCO and the 90° coupler will be presented and compared with the simulation results.

60-GHz hybrid system-on-package receiver front-end for low-cost high data rate radios

This paper presents a proof-of-concept low-cost 60-GHz receiver front-end using alumina-based hybrid System-on-Package (H-SoP). The development cycle of the proposed H-SoP is significantly shorter than that of conventional LTCC (Low Temperature Co-fired Ceramic) or IPD (Integrated Passive Devices) packaging technologies, also, the fabrication cost of H-SoP is less than that of LTCC or IPD. As an application of the proposed H-SoP, a 60-GHz receiver front-end which includes bandpass filter, low-noise amplifier, and a mixer is developed using active and passive building blocks from different technologies to optimize cost and performance. The experimental results exhibited an error-vector-magnitude of less than 6% for a 64-QAM OFDM signal over 60-GHz. The measured results confirm the potential of the proposed alumina H-SoP for low-cost, high-performance, short development cycle 60-GHz radio front-ends.