Current studies have demonstrated the design, layout, and performance of a prototype osmotic sensor in vitro using an affinity assay solution for up to four weeks. The small physical size conforms to an injectable device, forming the basis of a conceptual monitor that offers a tight glycemic control of BG.

An embedded air cavity in low temperature cofired ceramics (LTCC) is used to achieve a wideband response with stacked patch antennas. A single LTCC stacked patch antenna achieves a gain of better than 5 dBi over an 18% bandwidth with a good impedance match. A 2 2 element array of stacked patches is also realized, and achieves a 3-dB gain bandwidth from 25 to 30 GHz with a maximum gain of 11.1 dBi.

Purpose -The purpose of this paper is to investigate the effect of electroless NiAu (ENIG) deposition on the failure mechanisms and characteristic lifetimes of three different non-collapsible lead-free 2nd level interconnections in low-temperature co-fired ceramic (LTCC)/printed wiring board (PWB) assemblies. Design/methodology/approach -Five LTCC module/PWB assemblies were fabricated and exposed to a temperature cycling test over a 2 40 to 1258C temperature range. The characteristic lifetimes of these assemblies were determined using direct current resistance measurements. The failure mechanisms of the test assemblies were verified using X-ray and scanning acoustic microscopy, optical microscopy with polarized light, scanning electron microscope (SEM)/energy dispersive spectroscopy and field emission-SEM investigation. Findings -A stable intermetallic compound (IMC) layer is formed between the Ni deposit and solder matrix during reflow soldering. The layer thickness does not grow excessively and the interface between the layer and solder is practically free from Kirkendall voids after the thermal cycling test (TCT) over a temperature range of 2 40 to 1258C. The adhesion between the IMC layer and solder matrix is sufficient to prevent separation of this interface, resulting in intergranular (creep) or mixed transgranular/intergranular (fatigue/creep) failure within the solder matrix. However, the thermal fatigue endurance of the lead-free solder has a major effect on the characteristic lifetime, not the deposit material of the solder land. Depending on the thickness of the LTCC substrate and the composition of the lead-free solder alloy, characteristic lifetimes of over 2,000 cycles are achieved in the TCT. Originality/value -The paper investigates in detail the advantages and disadvantages of ENIG deposition in LTCC/PWB assemblies with a large global thermal mismatch (DCTE $ 10 ppm/8C), considering the design and manufacturing stages of the solder joint configuration and its performance under harsh accelerated test conditions.

An experimental-low temperature cofired ceramic (LTCC) ferrite tape system is characterized using circuits that are fabricated from the very material under test. Such in situ circuits provide data that are thought to be more representative of the performance obtainable by more complicated circuitry that will eventually be made from the same material using the same fabrication method. Emphasis is placed on simple measurements that can be performed using a minimum amount of equipment. For the first time, a compact in situ LTCC solenoid transformer is used to measure the magnetostatic properties of the ferrite, yielding a measured saturation flux density of 230 mT, a remanence of 136 mT, and a coercivity of 688 A/m. The peak linear relative permeability of the ferrite is 97 and its Curie temperature is low, only 117 C. A novel two-port line-connected ring resonator is used to characterize the material in the 6-40 GHz range. At frequencies above 20 GHz, the relative permittivity of the ferrite is 11.0, whereas its loss tangent ranges from 0.002 to 0.004, demonstrating the ferrite's suitability for use in microwave and millimeter-wave circuitry.

Wide-angle coverage, fine angular resolution and low-power consumption are key characteristics of millimeterwave (mm-wave) short-range wireless systems, such as access points in fifth-generation (5G) cellular networks and automotive radars. In this paper, we present a 60-GHz switched-beam antenna system addressing all these requirements. It consists of two identical parallel-fed arrays of 8 slots, each fed by a passive pillbox beamformer. A switch network comprising four singlepole-multiple-throw (SPnT) switches excites one of the two arrays at a time and selects the radiated beam. The whole system is fully-integrated in a multilayer low temperature co-fired ceramic (LTCC) module. The antenna covers a scan range of about ±39 • in one plane using eleven beams, between 57 GHz and 66 GHz. The proposed architecture enables the simultaneous achievement of continuous coverage (beam crossover levels of about-3 dB) and of low sidelobe levels (SLLs). Dedicated numerical tools are used for a preliminary design of the antenna. The design procedure, the technological development and the experimental results are discussed in detail. Index Terms-switched-beam antenna, millimeter-wave antennas, 5G, 60-GHz communications, low temperature co-fired ceramic (LTCC).