Azmi Ibrahim

The microstrip coupled line Bandpass filter using LTCC technology for 5GHz wireless LAN application

This paper presents a top-down design of the microstrip coupled line Band pass filter (BPF) embedded in low temperature co-fired ceramic (LTCC) for 5 GHz wireless LAN applications. It includes the design, simulation, fabrication and measurements. The filter circuit was designed and simulated based on Agilent Advanced Automation (ADS2005A) software. Then, the physical dimensions of components and the filter itself is subsequently determined and the physical design is later performed in the layout window of Empire XcCEL. All measured simulations are analyzed and compared to design specifications and characteristics (curve fitting). Any inaccuracy is taken into account where corrected design is further recovered.

An LTCC design technique based on FDTD EM simulations

This paper described the Low Technology Co-fired Ceramic (LTCC) design methodology at TMRND based on FDTD EM simulations that are required when designing the RF/microwave circuit. In this paper, 3D EM analysis and optimization with Finite Different Time Domain (FDTD) software Empire XcCeltrade from IMST was applied to achieve accurate modeling of the RF/microwave circuit using LTCC technology. A multilayer spiral inductor was selected for discussion to show this LTCC design technique. The main elements of the LTCC design technique relies on three important guidelines; use accurate component models, link the circuit schematic to the layout to reduce errors and finally link the layout to an EM simulator to detect coupling problems.

Characterization of alumina-based LTCC composite materials: Thermal and electrical properties

The study on Low temperature co-fired ceramic (LTCC) has been widely investigated due to its potential as an advanced approach for packaging of electronics devices. This paper evaluates and discusses about the firing temperatures effect on the densification, thermal and electrical properties of the prepared LTCC material. The LTCC tape, which consists mostly of Al2O3 was fabricated using tape casting technique. Five layers of tapes were then stacked and air-fired at different temperatures of 840, 880, 920 and 960°C. All samples were characterized for thermal and electrical properties. The crystallinity and microstructure of all samples were studied using XRD and SEM respectively. Current investigations show that the changing of density or volume fraction of pores is the main reason for the dielectric properties shift. Meanwhile, the changing in lattice parameters is observed as the main reason in thermal diffusivity shift. The sample fired at 880°C has the best thermal and electrical properties with thermal diffusivity of about 0.62 mm2/s, dielectric constant (εr) of about 5.65 and dielectric loss, tan (δ) of about 0.003.

Design of Interdigital Band Pass Filter for WLAN applications using LTCC technology

The paper presents the design of Interdigital Band Pass Filter (IBPF) for WLAN applications at center frequency 2.45GHz. It was designed using a 3D EM simulation tool and fabricated on substrate Ferro A6S by using in-house process of Low Temperature Co-fired Ceramic (LTCC) technology. Simulated and measured results were presented. The pass band insertion loss of the filter was measured to be −1.66dB at 2.45GHz within the specification, S21< −3dB. The return loss was measured at −15.57dB which better than specification, S11>−10dB.

Designing 5GHz microstrip coupled line bandpass filter using LTCC technology

A top-down detail design of a 5 GHz micro strip coupled line band pass filter in LTCC is presented in this paper. LTCC, which stands for low temperature co-fired ceramic is especially used for wireless and high-frequency applications. Now, the importance of LTCC is becoming more prominent in views of the fact a lot organizations has been funding R&D-projects regarding this new technology that focuses on larger implementation of functionality in LTCC substrates. Although Malaysia is new to this technology, its industry has certainly high hopes on the LTCC innovation to make a breakthrough and contribute significant benefits to the technology, industry, market and also, the country itself. The filter circuit was designed and simulated by using ADS2005A. Then, the physical dimensions of components and the filter itself is subsequently determined and the physical design is later performed in the layout window of Empire XcCEL. All measured simulations are analyzed and compared to design specifications and characteristics (curve fitting). Any inaccuracy is taken into account where corrected design is further recovered.

Q-band millimeter-wave SIW filter using LTCC technology

This paper describes technique for the design of Substrate Integrated Waveguide (SIW) filter using multilayer Low Temperature Co-fired Ceramic (LTCC) technology at Q-band frequency region. The design is based on a circular cavity structure operating at TM010 mode. A single order filter is chosen to demonstrate the feasibility of using in-house LTCC fabrication technology. Measured insertion loss of -1.954 dB and passband return loss of more than 10 dB at 38 GHz were achieved. Good filtering response is observed which shows that SIW filter using LTCC technology is a suitable candidate for implementation of filtering devices for a millimeter-wave uplink/downlink Remote Antenna Unit for a Radio-over-Fibre (RoF) system.

Multilayer End Coupled Band Pass Filter using Low-Temperature Co-Fired Ceramic Technology for Broadband Fixed Wireless

With the rapid growth of communications via the Internet, the need for an effective firewall system which has not badly affect the overall network performances has been increased. In this paper, a Field Programmable Gate Array (FPGA) -based firewall system with high performance has been implemented using Network FPGA (NetFPGA) with Xilinx Kintex-7 XC7K325T FPGA. Based on NetFPGA reference router project, a NetFPGA-based firewall system was implemented. The hardware module performs rule matching operation using content addressable memory (CAM) for higher speed data processing. To evaluate system performance, throughput, latency, and memory utilization were measured for different cases using different tools, also the number of rules that an incoming packet is subjected to was varied to get more readings using both software and hardware features. The results showed that the designed firewall system provides better performance than traditional firewalls. System throughput was doubled times of the one with Linux-Iptables firewalls.

Multiservice wireless network testbed design using SDR and RoF platforms

This paper presents a testbed design by using Software Defined Radio (SDR) and Radio-over-fiber (RoF) platforms for the next generation wireless access network. The proposed testbed supports concurrent multiservice transmissions, in which a heterogeneous network is emulated. The SDR is based on NI USRP RIOs, which generated both IEEE 802.11 and long term evolution (LTE) signals, and integrated with the RoF platform to demonstrate an end-to-end system transmission. The state-of-the-art polarization multiplexing technique is employed within the RoF system to enable multiservice transmission over single optical fiber with minimal interference. The advantage of employing SDR is to expedite the process of optimizing the network performance before replacing the system with commercial-of-the-shelf (COTS) products. This technique drastically reduces the complexity of the overall prototyping development, hence enhances the time-to-market of a new network.

Effect of insertion losses on millimeter-wave SIW filters using LTCC technology

This paper describes the study of insertion losses effect on millimeter-wave substrate integrated waveguide (SIW) filters of different degree fabricated on LTCC technology. First-, second- and third-degree filters were designed based on TM010 circular cavity structure operating at 38 GHz. It was observed that the losses variation across the passband increases proportionally by a factor of 1.4 as the degree of the filter increases. Hence, careful consideration between allowance for insertion losses and selectivity of filter specifications are needed when designing LTCC SIW filters at high frequencies.

Design of 40GHz multilayer end coupled band pass filter using LTCC technology

Multilayer end coupled band-pass filters (BPFs) using Low Temperature co-fired Ceramic (LTCC) technology have been presented as a parts of 40 GHz Remote Antenna Unit Downlink for Radio over fiber (RoF) system applications. In order to control the precise distance between two adjacent resonators, the resonators was vertically located on different layers. The BPFs were designed and fabricated by using Ferro A6S tape. Its dielectric constant and loss tangent are 5.8 and 0.002, respectively, at 40GHz. The overall size of the fabricated filter was 10.5 × 2.5 × 0.77 mm3. The measured insertion and return loss were 3.17dB and 18.53dB at 42GHz, respectively.