Jong-In Ryu

Design of a Label-Typed UHF RFID Tag Antenna for Metallic Objects

In this letter, we present a label-typed UHF RFID tag antenna for metallic objects. The antenna is fabricated on a thin flexible PET substrate with a thickness of 0.07 mm. In order to achieve good performance on metallic objects as well as in free space, the design of the proposed antenna is mainly considered for two factors; gain and impedance matching. To increase the gain of the proposed antenna, we place an additional loop, which has a line width of 2.5 mm and surrounds the original meandered folded dipole antenna. Also, the design is achieved by matching in frequency region where minimum impedance variation occurs on metallic objects, so that the change of the input impedance is small compared to free space case. The experimental results show that the maximum reading range of the proposed antenna is about 7.5 m in free space, and 3 m for 1-mm separation from the metallic surface. Furthermore, reading range has been compared among commercial and the proposed label-typed RFID tags, revealing about 3 times longer reading range than Alien M-tag when it is placed 1 mm above a metal surface.

High density and low-cost silicon interposer using thin-film and organic lamination processes

In this paper, a new low-cost silicon interposer technology is introduced. Organic lamination processes are used for multi-layer signals and through via-holes are made by adjusting UV laser drilling. It is possible to make a 80 μm minimum through via using laser drilling. The fabricated interposer has an only 230 μm thickness and it has more than 6 metal layers including thin film metal. In this interposer, thin film spiral inductors and MIM capacitors can be integrated in the silicon substrate. For low-loss and high isolation, a TOLV (Through Organic Lining Via) and COLV (Coaxial Lining Via) can be made. The fabricated coaxial via has very low loss, 0.07 dB at 10 GHz, and high isolation properties for a wide frequency range, more than 40 dB at 0~40 GHz.

The Andersson lesion in ankylosing spondylitis: DISTINGUISHING BETWEEN THE INFLAMMATORY AND TRAUMATIC SUBTYPES

A number of causes have been advanced to explain the destructive discovertebral (Andersson) lesions that occur in ankylosing spondylitis, and various treatments have been proposed, depending on the presumed cause. The purpose of this study was to identify the causes of these lesions by defining their clinical and radiological characteristics. We retrospectively reviewed 622 patients with ankylosing spondylitis. In all, 33 patients (5.3%) had these lesions, affecting 100 spinal segments. Inflammatory lesions were found in 91 segments of 24 patients (3.9%) and traumatic lesions in nine segments of nine patients (1.4%). The inflammatory lesions were associated with recent-onset disease; a low modified Stoke ankylosing spondylitis spine score (mSASSS) due to incomplete bony ankylosis between vertebral bodies; multiple lesions; inflammatory changes on MRI; reversal of the inflammatory changes and central bony ankylosis at follow-up; and a good response to anti-inflammatory drugs. Traumatic lesions were associated with prolonged disease duration; a high mSASSS due to complete bony ankylosis between vertebral bodies; a previous history of trauma; single lesions; nonunion of fractures of the posterior column; acute kyphoscoliotic deformity with the lesion at the apex; instability, and the need for operative treatment due to that instability. It is essential to distinguish between inflammatory and traumatic Andersson lesions, as the former respond to medical treatment whereas the latter require surgery.

Implementation of a front-end-module by embedding a RF switch IC and a power amplifier in printed-circuit-board

This paper presents the implementation of a front-end-module (FEM) for wireless Local Area Network (W-LAN) by embedding a power amplifier module (PAM) and a double-pole-double-throw (DPDT) switch IC in printed-circuit-board (PCB) by sequential build up process using polymers. Polymers are adopted as substrates and these substrates are composed of FR4 and Ajinomoto-bonding-film (ABF). Vacuum lamination process is applied to get a planar surface and void free cavity filling. A proposed module consists of a matching stage for a PAM, a DPDT switch IC, a PAM and a Tx low-pass-filter (LPF) for rejecting 2nd harmonic of a PAM. All inductors and capacitors for a Tx LPF and for a matching stage are designed and embedded in PCB. Therefore, each component has 3-dimension (3-D) geometry in PCB and it is designed by using Sonnet simulator as 2.5-D simulation tool. The overall size of a module and of a tested board is given as 5 mm × 4 mm × 0.8 mm and 20 mm × 6 mm × 0.8 mm, respectively. PCB employs 12 copper layers. The measured Tx LPF insertion loss is better than 0.5 dB and the return loss is better than 28 dB from 2.4 GHz to 2.5 GHz. Its rejection for 2nd harmonic of PAM is more than 35 dB. The measured input impedance of a matching stage is 8.1 +11.6j. The measured adjacent-channel power ratios (ACPRs) of 1st side-lobe and 2nd side-lobe in the Tx output spectrum are 31.2 dBc and 59.9 dBc, respectively. An output 1-dB compression (P1dB) and gain are 15 dBm and 10.3 dB, respectively.

Investigation of an embedded RF switch IC in printed-circuit-board

This paper presents the interconnection performance of the embedded integrated-circuit (IC) in printed-circuit-board (PCB) against wire-bonding method. Embedding IC into PCB substrate, micro-vias were adopted to interconnect the IC to the substrate. In order to consider the RF performance of the interconnection used for embedding IC into the PCB substrate, a double-pole-double-through (DPDT) switch IC was selected as an embedded RF IC. The insertion loss (IL) and the return loss (RL) of each switch were measured in order to compare the wire-bonded switch IC to the embedded switch IC. As a result, the wire-bonded switch IL is better than 0.7 dB and the RL is 16.2 dB at 5 GHz. The embedded switch IL is 0.6 dB and the RL is greater than 33.5 dB at 5 GHz. In addition to this, the embedded switch RL is better than 25 dB until 7 GHz. Thus the micro-via interconnection of the embedded switch in PCB substrate demonstrated better the RF performance than wire-bonding method in perspectives of the RL and the IL. This paper presents the advantages of the embedded IC in PCB by using micro-via.

A novel integrated Tx-Rx diplexer for dual-band WiMAX system

In this paper, a novel integrated Tx-Rx diplexer for dual-band Worldwide Interoperability for Microwave Access (WiMAX) application is realized by low temperature co-fired ceramic (LTCC) technology. The proposed Tx-Rx diplexer has 5 ports and consists of two lowpass filters, two bandpass filters, and one common matching network, which are fully embedded in the LTCC substrate. This novel structure can be applied for either Tx or Rx path by simply making two ports to be shorted to the ground. The fabricated Tx-Rx diplexer has 9 pattern layers including 3 ground layers and it occupies less than 3.0 mm × 2.5 mm × 0.528 mm. In case of Tx operation, the measured insertion losses at 2-GHz and 5-GHz band are less than 0.9 dB and 2.5 dB, respectively, with a return loss of more than 19.4 dB and 10 dB. Furthermore, it provides a more than 32-dB and 19.2-dB second harmonic suppression at 2-GHz and 5-GHz bands is obtained. In case of Rx operation, the insertion losses are less than 1.4 dB and 2.4 dB in 2-GHz and 5-GHz bands. It provides a more than 30-dB and 32-dB attenuation at 2-GHz and 5-GHz band. The measured results of the implemented Tx-Rx diplexer are in good agreement with the simulated results. The RF FEM was realized by the proposed Tx-Rx diplexer and 4 PIN diodes at each port except antenna port for shortening to the ground or not. It can be low-loss and low-cost solution by removing MMIC SPDT switch in series connection.

Fabrication of a switch module by embedding chip capacitors and an active IC in organic substrate

This paper presents a switch module by embedding both chip capacitors and a single-pole-double-throw (SPDT) IC in organic substrate. A switch IC usually needs capacitors as decoupling capacitor. Input port or output port in a switch has DC voltage so that it is necessary DC block when a switch is connected with another IC or stages. Chip capacitors as DC blocks are employed in input and in output of a switch. Optimized capacitors are demanded as DC block capacitor between a switch and other IC. The value of capacitor is dependent on distance of transmission line and dielectric constant of substrate. An embedded IC is analyzed and modelled in order to design a proposed switch module. Embedded capacitors are compared with various capacitors by using modelling and simulation. A SPDT IC as a switch IC is employed and obtained from M/A Com. Proposed organic substrate is composed of Ajinomoto-bonding-film (ABF) and FR4. The total size of a fabricated module is 1.85 mm × 1.48 mm × 0.65 mm. This size is similar to a normal packaged SPDT IC in spite of embedding capacitors in a presented module. A proposed SPDT module consists of a SPDT die and three capacitors. Pad size of each port is die 50 um × 50 um and minimum pitch of pads is 25 um. The size of an embedded die is given as 320 um × 550 um × 160 um. Chip capacitors, 0.6 mm × 0.3 mm × 0.3 mm, are adopted. The drill sizes of blind-via and thru-via is 40 um and 100 um, respectively. Two compact switch modules which embedding an active IC and chip capacitors were implemented and measured. Implemented samples were measured by Agilents N5230 network analyser and Cascades probe station. As a result, insertion loss is better than 0.71 dB from 1 GHz to 3 GHz. Return loss is better than 21.6 dB. Good performance was obtained. Active frequency range can be approximately extended to 3 GHz

A mobile TV/GPS module by embedding a GPS IC in printed-circuit-board

GPS and mobile TV are widely used in a lot of portable device, navigation, and mobile phone. As this solution, this paper presents a compact module for a mobile TV with GPS by using system-on-package (SoP) technology. In order to implement a slim and compact module, a GPS chip is embedded in printed-circuit-board (PCB) and a mobile TV IC and other components are mounted in PCB. This module is composed of a mobile TV IC, a GPS IC, a BPF, a crystal, regulators, shunt capacitors, series inductors, and a loop filter. This module uses lamination process and a GPS IC is embedded by using chip-first process. Polymer substrate consists of epoxy core as core substrate and ajimoto-bonding film (ABF) to bond each layer. Three times lamination and via drill/Cu plated are proposed. The dimension of a GPS IC is 3.5 mm × 3.2 mm × 0.32 mm. An IC is positioned in epoxy core. The thickness of epoxy cores, two kind of ABFs, 350 um, 40 um, and 20 um are applied, respectively. 0.6 mm thickness is obtained in this paper by embedding an IC. In order to check the performance and size for embedded modules, two representative modules for mobile TV/GPS with surface mounting technology (SMT) and with SoP technology are designed and compared. The size of module with SMT and SoP are as 16.5 mm × 11.5 mm × 1.1 mm and 13.5 mm × 12.5 mm × 1.1 mm, respectively. Almost 11 % size reduction is obtained by SoP. A presented module for a mobile TV/GPS was measured by DVB-TDMB test set and GPS program. Rx sensitivity of a mobile TV and a GPS is measured as -92 dBm and -162 dBm/Hz, respectively. Mobile broadcast and GPS information are well received and performed in commercial field. As a result, SoP technology was better than SMT technology in a view of size under good performance.

Fabrication and characterization of embedded active and passive device for wireless application

In this study, the research of embedded active and passive package is carried out for miniaturized wireless module. We fabricated very small RF module which one bare chip (0.3mm × 0.5mm, SPDT switch IC) and three 0603(0.6mm × 0.3mm, MLCC) passive devices were buried into within 1.85mm × 1.5mm substrate. Used materials were compatible with PCB process such as polymer laminating, dry film patterning, electroless-electrolytic copper plating and atmospheric plasma treatment. We studied low pressure bonding process using rheology dependence of polymer on temperature to prevent fracture or crack from embedding chips into PCB. The embedded chip and passives were electrically interconnected by small laser via(30µm) and Cu pattern plating process after atmospheric pressure plasma treatment, which revealed an effect on filling of micro via and shape of fine pattern. The interconnection between chip pad and Cu were evaluated by SEM image, which shows Cu pattern of PCB and pad of passive was interconnected without intermetallic formation. However, intermetallic, Cu-Sn-Ni, formed between passive electrode and plated Cu layer, and molten Sn is segregated along the wall of via hole after reflow. DSC (Differenntial Scanning Calorimetry) analysis was employed to calculate and optimize the amount of curing. Polymer showed maximum 90° peel strength (~0.7kgf/cm) with Cu pattern when Cu is plated on polymer after pre-curing was 80~90% completed. The RF characterization of embedded chip PCB was evaluated by measuring s-parameters (S11; return loss and S21; insertion loss). Return loss was below 20dB up to 4GHz. As a results, the embedded chip module is able to be applied for 2~5 GHz frequency application (Bluetooth and WiFi) with small size and good performance.

A miniaturized module for Bluetooth low energy by embedding all passive components

This paper presents a compact module for a Bluetooth Low Energy (BLE) by embedding all passive components as capacitors, inductors, and resistors. Passive or active components are embedded in printed-circuit-board (PCB) as called as System-on-Package (SoP). A proposed module is composed of a BLE IC, a memory, a 3-axis sensor, a crystal, inductors, capacitors, and resistors. In side view, ICs and a PCB with passive components are sequentially located from top and bottom. Capacitors, inductors and resistors are embedded in PCB. In order to check the performance and size for embedded modules, two representative modules for BLE with SMT and with SoP are designed and compared. The size of module with SMT and SoP are as 11 mm × 8 mm and 6 mm × 8 mm, respectively. Almost 44.5 % size reduction is obtained by SoP. Measured Tx power in Bluetooth are given as −2.0 dBm and BLE has good performance. This paper presented that SoP technology was better than SMT technology in a view of size. Implemented module had good performance and slim size.