Improvement of integrated dipole antenna performance using diamond for intra-chip wireless interconnection

In this paper, a linear on-chip dipole antenna pair on Si substrate is analyzed and simulated to investigate the transmission characteristics using CST MICROWAVE STUDIO. By inserting a 1.4 mm thick diamond layer between substrate and heat sink, the obtained transmission gain of antenna pair of length 4mm with 3mm separation on 10 Ohm-cm Si substrate increases by 12dB at 14GHz and for 1.5mm thick beryllia layer transmission gain increases 12 dB at 14.5 GHz. The effect of the dielectric materials like diamond, AlN, Alumina, beryllia, Taconic CER-10 and Arlon AR 1000thickness, substrate resistivity and the separation of an antenna pair on the transmission gain has been investigated. The results indicate that for highly dielectric materials of low electrical conductivity but high thermal conductivity, the transmission gain increases in real interconnection systems.

A wireless link was created using two identical antennas deposited on the substrate at the transmitting and receiving sides as shown in Fig.1a. To investigate effect of the environment existing between the transmitting and receiving antennas, several simulations were performed; one without any wired interconnections and other for different widths of the wired interconnections (w i ). The frequency range used for the simulations was from 20 GHz to 30 GHz. The result of simulations concerning the transmission gain between the transmitter and the receiver is shown in Fig. 2a. Note that the case of no wired interconnections is presented in Fig. 2a as w i =0. The distance between the two antennas (d) was assumed to be 10 mm in this case, as measured between the end-to-end antenna structures. It is clear from Fig. 2a that the transmission gain is larger than −20 dB across the band 21 GHz to 27 GHz for the case of no wired interconnection and between 22 to 28 GHz for the case of wired interconnection. The gain is at least 10 dB larger than the reported results in the literature when using other types of antennas, such as the monopoles, dipoles or zigzag dipoles [3]. This result indicates clearly the possibility of using the proposed antenna to establish a wireless interconnection even with packages that have a relatively large size. It is also interesting to compare the transmission gain with the conventional wired interconnections (when the wireless link is replaced by the wired link). To this purpose, the results published in [11] were interpolated. For a distance of 10 mm, the conventional wired interconnections described in [11] offered a transmission gain less than −28 dB at frequency of 25 GHz.

For our investigation of UWB dipole antennas as integrated circuit wireless interconnects, a pair of aluminum dipole antennas were fabricated on oxidized Si substrates with resistivity of 10 /spl Omega/.cm. Their feature sizes are: 1.0-6.0 mm length; 10 /spl mu/m width; 3.0 mm separation; 1 /spl mu/m thickness. A transmitter dipole antenna was driven by a Gaussian pulse or monocycle pulse. The pulse shape at the receiver dipole antenna was measured by a sampling oscilloscope through baluns, 180/spl deg/ hybrid couplers. It was found that the received waveform was the time derivative of the input Gaussian pulse because two baluns in the measurement circuit acted as time derivative devices. Consequently, the transmitter antenna input waveform and the receiver antenna output waveform were found to be identical, so that the Si integrated antennas could be used for UWB communication in an integrated circuit chip with Gaussian pulses.

Novel structuring technique for diamond coatings

In this paper, a theory based on dual‐feedback circuit methodology is adopted to explain the anomalous dips of scattering parameter S22 in deep sub‐micrometer MOSFETs. It is found that the output impedance intrinsically behaves as a series RC circuit (for low substrate resistance) or a “shifted” series RC circuit (for very high substrate resistance) at low frequencies, and a parallel RC circuit at high frequencies. This inherent triple characteristic of the output impedance can cause two types of anomalous dips of S22 in a Smith chart. In this way, the two experimental results [1, 2], that is, the anomalous dips caused by high substrate resistance and high trans‐conductance (or wide gate‐width), can be explained simultaneously for the first time. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 193–200, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10718

The study here compares and evaluates the performance of different antennas such as the dipole, Yagi-Uda, and helical antennas in the context of FM broadcasting. The main goal here is to compare how these antennas perform in terms of signal strength and efficiency. The study carried out experiments in a controlled environment and tested the antennas in an outdoor environment by scanning the FM band from 88 to 108 MHz. The experiments were conducted in a similar environment to compare the performance of these antennas. The parameters taken for the study were gain in dBi, SNR, RSSI, bandwidth efficiency, and radiation pattern stability. The results obtained from the experiments show that the dipole antenna performed at an average gain of 2.1 dBi and an RSSI of -64 dBm at a distance of 1 km. The study also found that the SNR for the dipole was 18.4 dB. The results obtained from the experiments show that the dipole antenna performed well at a distance of 3 km. The performance of the dipole antenna was average. The study also found that the Yagi-Uda antenna performed very well in terms of directional efficiency. The results obtained from the experiments show that the Yagi-Uda antenna performed at an average gain of 9.6 dBi and an RSSI of -47 dBm at a distance of 1 km. The study also found that the SNR for the Yagi-Uda antenna was 27.8 dB. The results obtained from the experiments show that the Yagi-Uda antenna performed very well at a distance of 8.5 km. The study also found that the helical antenna performed at an average gain of 6.2 dBi and an RSSI of -55 dBm at a distance of 1 km. The study also found that the SNR for the helical antenna was 23.1 dB. The results obtained from the experiments show that the helical antenna performed very well at a distance of 6.2 km. The study found that the helical antenna performed better in an environment with buildings and foliage. The study concluded that the choice of the antenna depends upon the requirements. The study concluded that the Yagi-Uda antenna should be used for long-distance and high-gain requirements. The study concluded that the helical antennas should be used for difficult propagation environments. The study concluded that the dipole antennas should be used for economical requirements.

The effects of the resistivity and crystal orientation on the leakage current and radiation response characteristics have been studied. The detector with (111) oriented substrate shows higher leakage current than (100) orientation due to the higher interface trap density at the Si/SiO2 interface. And high resistive substrate shows larger leakage current than low resistive one because of its wider depletion width at the same bias voltage. However, in case of (100) oriented substrate, the leakage current of low resistive substrate is larger than high resistive substrate at high reverse bias. It seems that thermionic field emission (TFE) current for low resistive substrate increased at high reverse bias. To compare the charge generation and collection for the radiation, we irradiated an X-ray beam to each detector and read the output current. The detector with (111) oriented substrate shows 20% higher output current than (100) orientation and it is independent on the resistivity of the substrates. The most influential factor on the output current is the thickness of the wafer. From the results we can suggest a high resistive, (100) oriented and thick wafer for direct type radiation detector, and a low resistive and thin wafer for in-direct type detector. Finally, we assembled our detector with read-out integrated circuit for the application of gamma ray dosimeter and our detector is very sensitive to Cs137 natural gamma ray.

In atomic force microscopy (AFM), sharp and wear-resistant tips are a critical issue. Regarding scanning electrochemical microscopy (SECM), electrodes are required to be mechanically and chemically stable. Diamond is the perfect candidate for both AFM probes as well as for electrode materials if doped, due to diamond's unrivaled mechanical, chemical, and electrochemical properties. In this study, standard AFM tips were overgrown with typically 300 nm thick nanocrystalline diamond (NCD) layers and modified to obtain ultra sharp diamond nanowire-based AFM probes and probes that were used for combined AFM-SECM measurements based on integrated boron-doped conductive diamond electrodes. Analysis of the resonance properties of the diamond overgrown AFM cantilevers showed increasing resonance frequencies with increasing diamond coating thicknesses (i.e., from 160 to 260 kHz). The measured data were compared to performed simulations and show excellent correlation. A strong enhancement of the quality factor upon overgrowth was also observed (120 to 710). AFM tips with integrated diamond nanowires are shown to have apex radii as small as 5 nm and where fabricated by selectively etching diamond in a plasma etching process using self-organized metal nanomasks. These scanning tips showed superior imaging performance as compared to standard Si-tips or commercially available diamond-coated tips. The high imaging resolution and low tip wear are demonstrated using tapping and contact mode AFM measurements by imaging ultra hard substrates and DNA. Furthermore, AFM probes were coated with conductive boron-doped and insulating diamond layers to achieve bifunctional AFM-SECM probes. For this, focused ion beam (FIB) technology was used to expose the boron-doped diamond as a recessed electrode near the apex of the scanning tip. Such a modified probe was used to perform proof-of-concept AFM-SECM measurements. The results show that high-quality diamond probes can be fabricated, which are suitable for probing, manipulating, sculpting, and sensing at single digit nanoscale.

In this work, we have shown enhancement of intra-chip transmission between wireless interconnects, which are implemented as antenna-on-chip (AoC), using Jerusalem-Cross Artificial Magnetic Conductor (JC-AMC). AoCs are located at the center of four-quadrants of a multicore chip. For each quadrant, a zigzag monopole AoC above a JC-AMC surface is simulated to resonate at 30GHz with a return loss of −13dB. The enhancement is almost 3dB for two out of three antenna pairs. This enhancement has almost doubled the received power at the antenna with JC-AMC which is beneficial when designing on-chip integrated transceivers. For experimental validation, fabrication of the zigzag antennas with JC-AMC surfaces on silicon wafer are under progress.

Silicon-On-Diamond layer integration by wafer bonding technology

The characteristics of a small-size integrated dipole antenna on Si have been evaluated for use in inter-chip wireless interconnections and the measured characteristics are compared with the results obtained by 3D finite element simulation. The measured inter-chip transmission coefficients for a 0.02 mm2 dipole antenna pair manually separated by 10.5 mm each other in the horizontal plane and in a omit plane where the receiver chip is 2.6 mm higher than the transmitter chip were -42.7 dB and -57.5 dB at 20 GHz when the antennas were fabricated on a high-resistivity Si substrate and on standard Si substrate, respectively. This shows the feasibility of using integrated dipole antennas for wireless clock distribution and data transmission in future 3D ICs or in stacked chip scale packaging.

A comparison on radiation tolerance of microstrip detectors built on [formula omitted] and [formula omitted] silicon substrates after proton irradiation

In this research article, a comprehensive simulative work has been made to investigate the performance of a dipole antenna using two parameters: Permittivity and Radiation pattern. Firstly, a 1m Cu dipole antenna is designed to evaluate the performance. Secondly, to inspect the efficiency of the antenna, return loss, VSWR, reflection coefficient, mismatch loss and port current are taken into consideration. It is found form the simulative study that it provides near to zero effect on the considered characteristics in case of 2-4.5 permittivity of the antenna material. In this region of the permittivity, the port current remains constant and the value is around 0.01205A. The radiation pattern of the antenna has been noticed by changing frequency 7.494811 MHz to 134.9066 MHz. The simulation work is made by using Matlab2018a and Comsol Multi-Physics simulation software.

This paper demonstrates the comparison between two on-chip antennas, circular microstrip patch antenna (CMPA), and cylindrical dielectric resonator antenna (CDRA), planned for operation at 60 GHz and integrated into 0.18-µm CMOS integrated circuits. The antennas are fed with similar feeding networks. The bandwidth for a return loss below −10 dB is 17.9 % for CMPA and 21 % for CDRA. The simulated radiation patterns of both antennas exhibit similar properties. The gain of the CDRA is 2.2 dB higher than CMPA. Likewise, the results show that the radiation efficiency of CDRA is significantly higher than that of the CMPA at 60 GHz. A comparative study on the transmission gain for wireless interconnections using CMPA and CDRA in the cases of intra- and inter-chip interconnections is investigated. Transmission gain proves the superiority of CDRA compared to CMPA. The proton implantation technique is used to improve the transmission gain. The silicon substrate resistivity is increased from 10 Ω-cm up to 10 MΩ-cm.

Apparatus for the investigation of low and high-T/sub c/ superconducting spirals has been designed and built. The device is capable of measuring the characteristic of superconducting spirals. The superconducting spirals are on a normally conducting substrate. The normally conducting substrate serves as a shunt between the superconducting turns, serving as a distributed quench protection resistor. Samples with both high and low electrical resistance substrates have been tested on this apparatus. Preliminary results of the tests of both high-T/sub c/ (Bi-Sr-Ca-Cu-O) and low-T/sub c/ (Nb-Ti) thick-film spirals have been investigated. Current distribution in films during quench has been studied experimentally. Generation of normal zone and hysteresis current-voltage characteristics have been discovered in high-T/sub c/ superconducting spirals on silver plate. It is shown that frequency of generation of normal zone depends at under certain conditions (transient current, magnetic field, temperature and resistivity of substrate). The results are being analyzed with models.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>