Wonil Chang

Monolithic LTCC SiP transmitter for 60GHz wireless communication terminals

We demonstrate a 36 times 12 times 0.9mm3 sized compact monolithic LTCC SiP transmitter (Tx) for 60GHz-band wireless communication terminal applications. Five GaAs MMICs including mixer, driver amplifier, power amplifier and two of frequency doublers have been integrated onto LTCC multilayer circuit which embeds a stripline BPF and a microstrip patch antenna. A novel CPW-to-stripline transition has been devised integrating air-cavities to minimize the associated attenuation. The fabricated transmitter achieves an output of 9dBm at a RF frequency of 60.4GHz, an IF frequency of 2.4GHz, and a LO frequency of 58GHz. The up-conversion gain is 11.2dB; while the LO signal is suppressed below 33.4dBc, and the spurious signal is also suppressed below 27.4dBc. This is the first report on the LTCC SiP transmitter integrating both a BPF and an antenna. A 60 GHz communication was demonstrated

60-GHz System-on-Package Transmitter Integrating Sub-Harmonic Frequency Amplitude Shift-Keying Modulator

This paper proposes a simple low-temperature co-fired ceramic (LTCC) integrated transmitter using sub-harmonic amplitude shift-keying modulation for 60-GHz wireless communications applications. The transmitter system-on-package (SoP) has been monolithically implemented with a six-layer LTCC block embedding a resonator, modulator, and antenna and two active circuits, including a negative resistance generator and frequency doubler on the block. The transmitter SoP integrating whole millimeter-wave circuitry is as small as 26 times 18 times 0.6 mm3, which needs external interfaces only for supplying dc power and digital input signal. The fabricated transmitter SoP reveals a bit error rate of 10-11 and good eye pattern through a 2.5-m transmission of 800-Mb/s data.

A very compact 60GHz transmitter integrating GaAs MMICs on LTCC passive circuits for wireless terminals applications

A 60GHz-band transmitter system-in-package (SiP) has been developed for future wireless communications applications. GaAs MMIC chipsets including a power amplifier, a driver amplifier, a mixer, and multipliers have been integrated on a LTCC multi-layer circuit for the heterodyne transmitter. The size of the whole transmitter LTCC module is 10mm /spl times/ 21mm /spl times/ 1mm. With an IF frequency of 2.4GHz and a LO frequency of 58GHz, 60.4GHz output of 11dBm is achieved, and the total gain is 12 dB. The link test for a 60GHz wireless communication shows that the transmitter communicates well with the receiver without any signal distortion.

Description of shape patterns using circular arcs for object detection

The authors propose a novel object detection algorithm based on shape matching using a single sketch of an object. The proposed algorithm uses circular arc segments to describe image edges; this approach is advantageous for shape description, shape expression and reconstruction. Circular arcs are initially segmented from the image contour using the split-and-merge method, and they are extended, being partially overlapped with neighbouring circular arcs. The extracted circular arcs of the object sketch constitute an attributed relational graph as a structured object model. Circular arcs in the test image are refined by the bottom-up process of circular arc extension, and matched with circular arcs in the object model by the top-down process of end-point adjustment. The authors design end-point-based shape descriptors to encode local shape information. Hough voting aggregates the detection of circular arcs to localise the object. Probabilistic relaxation verifies the detection candidates and delineate the object boundaries. The proposed object detection system benefits from reliable extraction of contour segments, efficient and discriminative shape encoding, and flexible and robust shape matching. It exhibits competitive object detection performance in experiments using real images.

Joint Estimation of Multiple Notes and Inharmonicity Coefficient Based on

With the increasing importance of smart gadgets in our daily lives, there is a need for an automatic piano transcription system in various multimedia services. For automatic piano transcription, the string inharmonicity coefficient (B) and fundamental frequency (f0) should be detected robustly and accurately. The proposed triplet-sequentially additive partial (SAP) algorithm improves the current B estimation algorithm in terms of both performance and speed with less prior knowledge. Additionally, this joint (B, f0) estimation algorithm is applied directly to the transcription of real piano recordings, and the 4.41% improvement of accuracy was achieved over another transcription system that had both similar processing steps and feature extraction method.

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An SMD type balun with a frequency range from 10 GHz to 25 GHz in a low temperature co-fired ceramic (LTCC) substrate is designed and measured. To reduce the effect of misalignment in the multilayer coupler, we propose a novel multilayer coupler structure which is insensitive to misalignment. The package has ports on the ground plane for the SMT, and a cover on top of the circuit to protect the circuit. Every transmission line is simulated as an embedded micro-strip line to account for the cover effect. All the internal ports are connected to the output ports at ground plane through via transition. The total number of LTCC layers is 5 including the cover layer. The overall dimension is as small as 5.5 mm /spl times/ 5.5 mm /spl times/ 0.5 mm.

-Triplet for Automatic Piano Transcription

A 60GHz surface wave reduced type antenna is presented which can be used in a 3D system in package (SiP) with a low temperature co-fired ceramic (LTCC) substrate. Using a simple magnetic current model, we derive the surface wave reduction condition of our design and show that the LTCC substrate has a very similar condition to the derived condition. Using the result, we design a very simply structured surface wave reduced circular patch antenna. The conventional rectangular patch array antenna is also designed and measured for the purpose of comparison with the designed surface wave reduction type antenna.

A K-band LTCC SMD type balun using a multi-layer coupler insensitive to misalignment

In this paper, we propose a low loss 60GHz Radio AiP (Antenna-in-Package) solution for mobile applications. To achieve this low loss AiP, essential passive elements such as transmission lines, transitions, filters and antennas are developed using low temperature co-fired ceramic (LTCC). In order to make packages power efficient, air cavities are inserted; insertion loss is improved by up to 58% for stripline (SL). In order for them to be integrated into mobile devices, planar patch array antennas are developed as 2×1, 2×2, and 4×4 configurations. They show relative gains of 7 dBi, 7 dBi and 14 dBi, and 3 dB beam width of 30°, 36°, and 19°. We deal with interconnection issues with the wire-bonding technique. In conjunction with proper compensation circuits, 0.64dB of insertion loss is realized over the wide bandwidth (53∼67GHz). In order to realize low power 60GHz radio for mobile applications, an OOK modulator and demodulator are developed in CMOS technology. These can handle the data at Gbps (2Gbps and 5Gbps, respectively) speed with low power dissipation (14.4mW and 14.7mW, respectively). In the end, we demonstrate a low power 60GHz Radio AiP solution for video streaming in mobile applications.

A surface wave reduced higher mode circular patch antenna for 60GHz LTCC SiP

Perception of symmetric image patterns is one of the important stages in visual information processing. However, local interference of the input image disturbs the detection of symmetry in artificial neural network based models. In this paper, we propose a noise-robust neural network model that can correct asymmetric corruptions and returns clear symmetry axes. For efficient detection of bilateral symmetry as well as asymmetry correction, our network adopts directional blurring filters. The filter responses are fed to oscillatory neurons for line extraction, which serializes the activation of multiple symmetry axes. Given an activated symmetry axis, the network estimates the difference of counterparts to generate a masking filter that covers the asymmetric parts. The network reconstructs the ideal mirror-symmetric image with complete symmetry axes by self-correction of corruptions. Through simulations on corrupted images, we verify that our network is superior to Fukushima’s symmetry detection network. Our network successfully presents biologically plausible and robust symmetry perception mechanism.

A low loss 60GHz radio integrating CMOS circuits with LTCC AiP

In this paper, we propose a symmetry axis detection network that can correct asymmetric parts by itself. Our network compares directional blurring of omnidirectional image edges, which plays a significant role in asymmetry detection and correction. The output layer consists of oscillatory neurons, which activates symmetry axes one by one. Given activated symmetry axis, network estimates the difference of image edges and generates a masking filter to cover the asymmetric parts. The network reconstructs ideal mirror-symmetric image with complete symmetry axes by self-correction. Our network models flexible symmetry perception of high-level cognitive function of human brain.