Increasing data rates, spectrum efficiency, and energy efficiency have been driving major advances in the design and hardware integration of RF communication networks. In order to meet the data rate and efficiency metrics, fifth-generation (5G) networks have emerged as a follow-on to 4G and projected to have $100\times $ higher wireless date rates and $100\times $ lower latency than those with current 4G networks. Major challenges arise in the packaging of radio frequency front-end modules because of the stringent low signal-loss requirements in the millimeter-wave frequency bands, and precision-impedance designs with smaller footprints and thickness. Heterogeneous integration in 3-D ultrathin packages with higher component densities and performance than with the existing 2-D packages is needed to realize such 5G systems. This article reviews the key building blocks of 5G systems and the underlying advances in packaging technologies to realize them.

A Review of 5G Front-End Systems Package Integration

The invention is directed towards an indicator circuit. The indicator circuit includes a ground plane; an antenna; a decoupler component; and an integrated circuit. The antenna includes at least one antenna trace; a first antenna terminal; and a second antenna terminal. The decoupler component includes a first decoupler component terminal and a second decoupler component terminal. The integrated circuit is electrically coupled to the first antenna terminal and the second antenna terminal. The integrated circuit is electrically coupled to the first decoupler component terminal. The second decoupler component terminal is electrically connected to the ground plane.

Indicator circuit decoupled from a ground plane

Novel types of narrow band filters based on the newly introduced gap waveguide technology are presented in this paper. The proposed filters have a central frequency of 35 GHz with approximately 1% fractional bandwidth. The filter resonators are composed of two separate plates and are manufactured by milling metallic blocks. The gap between the two metallic plates eliminates the need for electrical contact between them. This feature allows the resonators to be stacked in different layers. The filtering function is realized by producing a coupling between the stacked resonators. The measurement results of the manufactured filters are in good agreement with full-wave simulations, even without any tuning or adjustments.

Direct Coupled Resonator Filters Realized by Gap Waveguide Technology

The next generation wireless cellular network is aimed to address the demands of users and emerging use cases set by industries and academia for beyond 2020. Hence, The next generation 5G networks need to achieve very high data rates, ultra-high reliability, extremely low latency, energy efficiency and fully connected coverage. To meet these demands, ultra-dense networks (UDN) or ultra-dense heterogeneous networks (UDHetNet), millimeter wave (mmWave) and multicell cooperation such as coordinated multipoint (CoMP) are the three leading technology enablers. In this paper, we have made an extensive survey of the current literature on 5G wireless communication focusing on UDN, mmWave and CoMP cooperation. We first discuss the architecture and key technology enablers to achieve the goals of the 5G system. Subsequently, we make an in-depth survey of underlying novel ultra-dense heterogeneous networks, mmWave and multicell cooperation. Moreover, we summarize and compare some of the current achievements and research findings for UDHetNet, mmWave and CoMP. Finally, we discuss the major research challenges and open issues in this active area of research.

Next generation wireless cellular networks: ultra-dense multi-tier and multi-cell cooperation perspective

Fully printed 3D cube-shaped multiband fractal rectenna for ambient RF energy harvesting

Transmission zeros are used to improve the roll-off factors of filters but as a consequence, the out-of-band rejection decreases. In this work, an LTCC filter design is presented which employs a series inductor (implemented as a via hole) to improve the out-of-band rejection by introducing a third transmission zero. The filter, designed for GPS band (1.57 GHz), has one of the smallest reported foot prints ( (0.063×0.048×0.005)λg) and demonstrates the highest roll off factor (16.7 dB/100 MHz) for this band. With only four LTCC layers, the design is cost effective and thus highly suitable for miniaturized, ultra-thin system-on-package applications.

A 3-D Miniaturized High Selectivity Bandpass Filter in LTCC Technology

Tunable filters that are based on ferrite materials often require large and bulky electromagnets. In this work, we present a tunable filter in the Ku-band, which is realized in multilayer ferrite LTCC substrate with embedded bias windings, thus negating the need of a large electromagnet. Also, because of the embedded windings, the bias fields are not lost at the air-substrate interface and therefore the field and current requirements are reduced by an order of magnitude as compared to the previously reported filters. A simulation strategy that uses full permeability tensor with arbitrarily directed magnetic fields has been used to model the filter on a partially magnetized ferrite substrate. Special attention has also been paid to approximate the non-uniform magneto-static fields produced by the embedded windings. The complete design is implemented in 10 layers of ferrite LTCC, making it the first magnetically tunable filter with embedded windings and extremely small size [(5 $\, \times \,$ 5 $\, \times \,1.1$ ) $ {\rm mm}^{3}$ ]. The filter demonstrates a measured tunability of 4% and an insertion loss of 2.3 dB. With the small form factor, embedded windings, and low bias requirements, the design is highly suitable for compact and tunable SoP applications.

Tunable Bandpass Filter Based on Partially Magnetized Ferrite LTCC With Embedded Windings for SoP Applications

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Behavioral modeling of RF front end devices in Simulink

Various methods and systems are provided for high Q, miniaturized LCP-based passive components In one embodiment, among others, a spiral inductor includes a center connection and a plurality of inductors formed on a liquid crystal polymer (LCP) layer, the plurality of inductors concentrically spiraling out from the center connection In another embodiment, a vertically intertwined inductor includes first and second inductors including a first section disposed on a side of the LCP layer forming a fraction of a turn and a second section disposed on another side of the LCP layer At least a portion of the first section of the first inductor is substantially aligned with at least a portion of the second section of the second inductor and at least a portion of the first section of the second inductor is substantially aligned with at least a portion of the second section of the first inductor

High Q, Miniaturized LCP-Based Passive Components

Tunable matching networks (MNs) are essential components for agile radio frequency systems. To optimally design such networks, the total area they cover on the Smith chart needs to be determined. In this paper, the coverage areas of typical MNs have been determined analytically for the first time. It has been found that the coverage area is encompassed by up to five arcs. Analytical expressions for the centers and radii for these arcs have been derived. The theoretical analysis is provided for four typical MNs and verified by circuit simulation and measured data. Moreover, a dynamically load-modulated power amplifier has been designed using the presented theoretical techniques, which demonstrates a measured improvement in the power added efficiency of up to 5% in the frequency range of (0.8–0.9) GHz.

/pdf/analytical-formulas-for-the-coverage-of-tunable-matching-194eqfq7f0.pdf

Eyad Arabi

Papers

A 3-D Miniaturized High Selectivity Bandpass Filter in LTCC Technology

Tunable Bandpass Filter Based on Partially Magnetized Ferrite LTCC With Embedded Windings for SoP Applications

Behavioral modeling of RF front end devices in Simulink

High Q, Miniaturized LCP-Based Passive Components

Analytical Formulas for the Coverage of Tunable Matching Networks for Reconfigurable Applications