scholarly journals A DC Circuit Model of Distributed Diodes on Active Substrate Boards for CAD Tools

Author(s):  
Pragnan Chakravorty

In the past few years, a new type of circuit board, named here as active substrate board (ASB), was introduced over circuit applications of diodes. Unlike a traditional printed circuit board (PCB), an ASB has its substrate made of a semiconductor. The inability of the traditional integrated circuit (IC) technology to integrate wavelength dependent radio frequency (RF) components triggered the advent of ASBs. These boards draw desirable features from IC as well as PCB technologies. Unprecedented challenges came up in modeling the different devices fabricated on an ASB owing to their large sizes and the presence of wideband microwaves. So far, modeling the effect of large sizes and ambient microwaves on DC bias of diodes have not been considered in scientific literature. Furthermore, the state of the art numerical simulators are unable to imitate the behavior of such diodes observed over measurements. Here, a semi-analytical, circuit model of distributed diodes on ASB is presented that is fairly accurate in predicting the actual behavior of the diodes. The model also opines a novel phenomenon where microwaves affect the DC characteristics of diodes with added resistances.

2021 ◽  
Author(s):  
Pragnan Chakravorty

In the past few years, a new type of circuit board, named here as active substrate board (ASB), was introduced over circuit applications of diodes. Unlike a traditional printed circuit board (PCB), an ASB has its substrate made of a semiconductor. The inability of the traditional integrated circuit (IC) technology to integrate wavelength dependent radio frequency (RF) components triggered the advent of ASBs. These boards draw desirable features from IC as well as PCB technologies. Unprecedented challenges came up in modeling the different devices fabricated on an ASB owing to their large sizes and the presence of wideband microwaves. So far, modeling the effect of large sizes and ambient microwaves on DC bias of diodes have not been considered in scientific literature. Furthermore, the state of the art numerical simulators are unable to imitate the behavior of such diodes observed over measurements. Here, a semi-analytical, circuit model of distributed diodes on ASB is presented that is fairly accurate in predicting the actual behavior of the diodes. The model also opines a novel phenomenon where microwaves affect the DC characteristics of diodes with added resistances.


2020 ◽  
Author(s):  
Pragnan Chakravorty

In the past few years, a new type of circuit board, named here as active substrate board (ASB), was introduced over circuit applications of diodes. Unlike a traditional printed circuit board (PCB), an ASB has its substrate made of a semiconductor. The inability of the traditional integrated circuit (IC) technology to integrate wavelength dependent radio frequency (RF) components triggered the advent of ASBs. These boards draw desirable features from IC as well as PCB technologies. Unprecedented challenges came up in modeling the different devices fabricated on an ASB owing to their large sizes and the presence of wideband microwaves. So far, modeling the effect of large sizes and ambient microwaves on DC bias of diodes have not been considered in scientific literature. Furthermore, the state of the art numerical simulators are unable to imitate the behavior of such diodes observed over measurements. Here, a semi-analytical, behavioral DC model of three dimensional (3D), distributed diodes on ASB is presented that is fairly accurate in predicting the actual behavior of the diodes. The model also opines a novel phenomenon of an AC affecting a DC with an added resistance.


2021 ◽  
Vol 21 (1) ◽  
pp. 64-70
Author(s):  
Jeong Hun Park ◽  
Moon-Que Lee

This paper presents a new dual-band diode mixer for the X- and K-bands. The proposed mixer consists of a pair of series-connected diodes and a frequency-dependent delay line that operates at 180° and 360° at the X-band of 10.525 GHz and at the K-band of 24.15 GHz, respectively. Without reconfigurable devices such as switches, the proposed mixer operates as a single-balanced diode mixer at the X-band and a subharmonically pumped antiparallel diode mixer at the K-band simultaneously. The designed circuit was implemented in a hybrid microwave integrated circuit using discretely packaged RF components on a microwave printed circuit board. The measurement results showed conversion losses of 6.5 dB and 16.6 dB at the X- and K-bands, respectively.


Author(s):  
William Ng ◽  
Kevin Weaver ◽  
Zachary Gemmill ◽  
Herve Deslandes ◽  
Rudolf Schlangen

Abstract This paper demonstrates the use of a real time lock-in thermography (LIT) system to non-destructively characterize thermal events prior to the failing of an integrated circuit (IC) device. A case study using a packaged IC mounted on printed circuit board (PCB) is presented. The result validated the failing model by observing the thermal signature on the package. Subsequent analysis from the backside of the IC identified a hot spot in internal circuitry sensitive to varying value of external discrete component (inductor) on PCB.


Author(s):  
Titus Oyedokun ◽  
Riana H. Geschke ◽  
Tinus Stander

Abstract We present a tunable planar groove gap waveguide (PGGWG) resonant cavity at Ka-band. The cavity demonstrates varactor loading and biasing without bridging wires or annular rings, as commonly is required in conventional substrate-integrated waveguide (SIW) resonant cavities. A detailed co-simulation strategy is also presented, with indicative parametric tuning data. Measured results indicate a 4.48% continuous frequency tuning range of 32.52–33.98 GHz and a Qu tuning range of 63–85, corresponding to the DC bias voltages of 0–16 V. Discrepancies between simulated and measured results are analyzed, and traced to process variation in the multi-layer printed circuit board stack, as well as unaccounted varactor parasitics and surface roughness.


2019 ◽  
pp. 139-145
Author(s):  
A. N. Mikhailov

A new type of single‑layer transrefleсtor structure based on microstrip reflective antenna array is described. The developed  device is a single‑layer printed circuit board on one side of which a system of printed reflectors is located, and on the other is  a polarization structure consisting of parallel metal conductors, in contrast to a microstrip reflectarray antenna. The shape and  geometrical dimensions of printed reflectors arranged in a rectangular or hexagonal (triangular) pattern are chosen in such a way  that they transform a spherical front of an incident vertically polarized electromagnetic wave into a flat front of reflected wave. In  the case of irradiation of the developed transreflector with a horizontal polarization wave, the printed structure makes minimal  electromagnetic energy loss during its passage. The results of characteristics modeling (including phase curves) of an element  of the reflective lattice in the W‑band for different angles of incidence of the wave on the planar structure under study are given.  Based on the results obtained, the sizes of the reflective elements of the transreflector, which provide for the correction of the  incident wave with the necessary phase discrete, are determined and an electrodynamic model of the transreflector antenna is  built. The simulation of the main radiation characteristics of the antenna with the developed single‑layer transreflector was carried  out.


Circuit World ◽  
2020 ◽  
Vol 46 (3) ◽  
pp. 215-219
Author(s):  
Akhendra Kumar Padavala ◽  
Narayana Kiran Akondi ◽  
Bheema Rao Nistala

Purpose This paper aims to present an efficient method to improve quality factor of printed fractal inductors based on electromagnetic band-gap (EBG) surface. Design/methodology/approach Hilbert fractal inductor is designed and simulated using high-frequency structural simulator. To improve the quality factor, an EBG surface underneath the inductor is incorporated without any degradation in inductance value. Findings The proposed inductor and Q factor are measured based on well-known three-dimensional simulator, and the results are compared experimentally. Practical implications The proposed method was able to significantly decrease the noise with increase in the speed of radio frequency and sensor-integrated circuit design. Originality/value Fractal inductor is designed and simulated with and without EBG surfaces. The measurement of printed circuit board prototypes demonstrates that the inclusion of split-ring array as EBG surface increases the quality factor by 90 per cent over standard fractal inductor of the same dimensions with a small degradation in inductance value and is capable of operating up to 2.4 GHz frequency range.


2020 ◽  
Vol 37 (4) ◽  
pp. 199-204
Author(s):  
Kamil Janeczek ◽  
Aneta Araźna ◽  
Wojciech Stęplewski ◽  
Marek Kościelski ◽  
Krzysztof Lipiec ◽  
...  

Purpose The purpose of this study is to design and fabricate a simple passive sensor circuitry embedded into a printed circuit board (PCB) and then to examine its properties. Design/methodology/approach A passive sensor transponder integrated circuit (IC) working in the high frequency (HF) 13.56 MHz frequency band was selected for this study. A loop antenna was designed to make the reported sensor circuitry readable. Next, the sensor circuitry was fabricated and embedded into a PCB with the proposed technologies. Finally, properties of the embedded structures were examined as well-functional parameters of the sensor circuitries. Findings The described investigation results confirmed that the proposed technologies using an epoxy resin or standard materials used for PCB’s production allowed to successfully produce sensors embedded into PCBs. This technology did not have a negative significant impact either on quality of solder joints of the assembled transponder IC or on functional properties of the embedded sensor. Apart from the identification data, the reported sensor can provide information about a selected property of its environment, e.g. temperature when its internal temperature sensitive element is used or other factors with the use of external sensitive elements, such as humidity. Research limitations/implications It is planned to carry on the reported investigations to examine other types of sensor circuitries capable of indicating e.g. humidity level and to evaluate influence of the proposed technology on their functional properties. Practical implications The reported sensor circuitries can be successfully used in electronic industry in internet of things systems not only to identify monitored electronic devices, but also to control selected parameters of external environment. This creates opportunity to detect device malfunction by detecting local temperature growth or to analyze its environment, which might allow to predict failure of controlled products using radio waves. This advantage seems to be extremely beneficial for applications, such as space, aviation or military, in which embedded sensor systems may lead to enhancing reliability of electronic devices by reacting on occurred failures in a more efficient way. Originality/value This study demonstrates valuable information for engineers conducting research on sensor components embedded into PCBs. The reported technologies are quite simple and cost-effective because of the use of standard materials known for PCB’s production or an epoxy resin which could be treated as an additional encapsulant material enhancing mechanical properties of the embedded sensor transponder IC.


2021 ◽  
Vol 72 (2) ◽  
pp. 113-118
Author(s):  
Miroslav Potočný ◽  
Viera Stopjaková ◽  
Martin Kováč

Abstract This paper deals with the development and experimental verification of a low-power AC/DC converter. The proposed solution is aimed at the sub 0.5 W output power domain, commonly encountered in applications such as always-on wireless sensing nodes. To implement the proposed converter topology, a prototype application specific integrated circuit was designed and manufactured in a high voltage 0.35 µm CMOS technology, able to handle the maximum voltage of up to 120 V. The proposed design was first analyzed by transistor-level simulations showing high power efficiency and low no-load consumption of the developed converter. To facilitate experimental verification and measurement, an printed circuit board with the necessary external components was developed, as the available technology is unable to handle the AC line voltage directly. While the developed converter operated well with decreased input AC voltage, reliability issues arose during operation with the full AC line voltage of 230 Vrms. These are linked to digital control circuitry of the implemented chip and could be addressed in the second manufacturing run in the future.


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