AM Antenna Research Articles

Additive manufacturing of IoT housings with integrated electronics

Additive manufacturing (AM) is an established fabrication method for diverse applications. Due to the versatile manufacturing possibilities, AM provides totally new approaches in designing objects. An emphasis in the field of research was set to the development of unique materials for AM. Among them, conductive filaments were examined for applications in printed electronics. The combination of new materials and the innovative design approach offered by AM generates a comprehensive field of applications. Promising applications can be found on the “Internet of Things (IoT)” sector. The development of connected products includes physical and electronic components. Traditionally, the fabrication process of these products is linear, thus, the design and the fabrication of the physical components is separated from the electronic part. To overcome this separation, an AM approach can be applied in the fabrication of IoT devices. This additive multi-material fabrication approach enables the fabrication of mechanical and electric components in one fabrication process. To prove this fabrication approach, antennas for IoT devices consisting of a supportive element and a antenna element for signal transmission were designed. The antennas were fabricated by material extrusion combining non-conductive and conductive filaments. Two different antennas (patch and arc antenna) were designed focusing on one specific frequencies range: 868 MHz (LoRa). To compare the AM antenna, reference antennas have been fabricated by etching. Antennas were characterized by simulation and measuring the return loss of the fabricated specimen. Finally, the transmission of a payload was tested in a real-world scenario. The tested antennas were able to transmit a payload, however, the return loss differed between the different designs and fabrication approaches. Nevertheless, the additive multi-material fabrication process enables an integrated production approach which led to functional devices. In this sense, electronics and physical components are merged into a truly smart product. Based on the findings, further applications of the hybrid approach will be investigated e.g., signal traces, passive electrical components to further strengthen the extensive application possibilities of additive manufacturing.Graphical abstract

Silicon solar cell under electromagnetic wave in steady state: effect of the telecommunication source's power of radiation

The characterisation of minority carriers' recombination parameters is important to design any optoelectronic component, since they play an important role in the device performance. Many diagnostic techniques, steady state, quasi-steady state, transient and modulation methods for both the experimental and theoretical measurement have been developed for the determination of single or several recombination parameters. Many studies on recombination and electrical parameters of solar cells under constant magnetic field and / or electric field in the bulk due to carrier concentration have been proposed with one or three dimensional approach. In previous works, we study the effects of electromagnetic waves on silicon solar cell recombination parameters by changing the distance between the 2 MW power of radiation AM antenna and the solar cell. This work presents a one dimensional study of the influence of telecommunication source's power of radiation on a silicon solar cell illuminated by a white light in steady state. The telecommunication sources which can be an AM radio antenna or a FM radio antenna radiate electromagnetic waves. Electric field intensity depends on the power of radiation and the distance between the electric field intensity measurement point and the antenna. The magneto transport equations of excess minority carriers are solved with new boundary conditions. New analytical expressions of minority carriers' density, photo-current density, back surface recombination velocity, intrinsic junction recombination velocity and photo voltage depending on electromagnetic field intensity are established. The effects of electromagnetic field on photo-current density, back surface recombination velocity, intrinsic junction recombination velocity and photo- voltage by making vary the antenna power of radiation are then analysed. We analyze also the effects of electromagnetic field on the electric power delivered by the solar cell to an external charge. Thus, using the maximum of electric power delivered by the solar cell to an external charge, we deduce the solar cell conversion efficiency. The analysis of electromagnetic field effects on the silicon solar cell put out the influence of AM radio antenna or FM radio antenna on recombination parameters.

자동차용 AM/FM/TDMB/GPS 통합 능동형 샤크 안테나

AM, FM, TDMB, GPS 수신용 자동차 전장 안테나를 설계하고 이를 제작하였다. AM 안테나는 페라이트 턴스타일 안테나로 설계하여 전방향 특성을 갖도록 하였다. FM, TDMB 수신용으로는 헤리컬 소자를 접은 접힌 모노폴 안테나로 설계하였다. 대역 확보를 위한 GPS 수신 안테나는 공기층 사다리꼴 마이크로스트립 패치 안테나로 설계하였다. 제작된 AM 수신용 안테나의 수신 신호 세기는 -65.7 dBm으로 기존의 외장형 폴 안테나의 -63.5 dBm과 비교하면 소형이면서도 유사한 수신 성능을 나타냄으로써 외장형 폴 안테나 및 glass 안테나 대체 품으로 적용할 수 있음을 보였다. FM 및 TDMB 수신 신호 세기는 각각의 중심 주파수에서 -55.66 dBm, -43.50 dBm 측정됨으로써 기존 안테나에 비해 5~10 dB 높은 특성이 나타났다. GPS 안테나에 대한 측정은 VSWR 2 : 1 기준으로 135 MHz의 넓은 대역 특성과 4.31 dBi의 이득이 측정되어, GPS 전 대역에서 일반 세라믹 패치 안테나의 이득보다 3~5 dB 높은 이득을 얻었다. A vehicle antenna for AM, FM, TDMB, GPS systems was designed and implemented. Omnidirectional AM antenna was designed by ferrite turn style antenna. For the FM and TDMB antenna, folded monopole antenna which helical is folded was applied. GPS antenna for the bandwidth achievement was designed by trapezoidal microstrip patch that has air substrate. Receiving signal strengths by the measurement were presented for the AM, FM and TDMB antenna. AM signal strength was -65.7 dBm, this strength is almost as same conventional pole antenna as -63.4 dBm. It can be replaced conventional pole or glass antenna by the studied antenna. Signal strengths for FM and TDMB were -55.66 and -43.50 dBm at center frequency, they are 5~10 dB higher than conventional antenna. Measurements of bandwidth and gain for the GPS antenna showed 135 MHz under VSWR 2 : 1 and 4.31 dBi, gains over GPS band were 3~5 dB higher than ceramic patch antenna.

MF AM antenna radiation pattern verification method by near field measurements

No other component of a broadcast system offers as many options in terms of performance and efficiency as the antenna system. The radiation pattern of a MF (medium frequency) antenna is one of the major characteristics to describe the performance of the system. To optimize the reach and effectiveness of broadcast antennas and to prove regulatory compliance it is essential to know their radiation pattern for a given operating environment. Consequently it is of great interest for the broadcaster to verify the specified patterns on the installed antenna system. A tried and trusted method is to fly a helicopter or a plane carrying special recording equipment to perform far field measurements over the site. Besides being costly, this is not always possible. In this article, ground based methods where the calculated radiation patterns are verified by near field measurements are presented. This method provides good results with less expenditure compared to the above mentioned airborne far field measurements.

MF digital AM station antennas

It is very important having the proper antenna, specially in the MF AM band where achieving the necessary bandwidth in the antenna impedance is a difficult task. This problem is critical in the lower frequencies were the antenna matching to the transmission line generally is very sharp and the best match is obtained only at the carrier frequency with an appreciable power reflection in the lateral frequency bands. This problem is not very important in the classical AM transmissions were the maximum transmitted power is located at the carrier frequency and only a fraction in the upper and lower lateral bands. Of course this produces some distortion in the AM transmission but in this case the quality of the audio is not really of high fidelity, like in an FM transmission, due to a lot of factors, one of them the lack of the full audio spectrum. This problem can be corrected with high fidelity audio transmitters and specially with digital transmission in order to achieve CD quality audio and here the transmitting antenna plays an important role. In this paper MF AM antenna systems are analyzed not only from the input impedance point of view, but with consideration of all the factors in order to determine the best system in bandwidth and radiation properties in different parts of the standard AM band. Cylindrical, type A, and Cantilever classical monopoles and the modern dipole type antenna systems are compared, to provide the criteria for choosing an optimum antenna for the future digital AM service. Examples of measured field strength as a function of distance in a flat region are presented in order to show the interesting MF AM possibilities for a digital service.

Short low loss AM antenna

An exploration is made of ways to improve the performance of a relatively small transmitting or receiving AM antenna system. Short vertical towers can be top-loaded to increase the radiation resistance and lower the base input capacitive reactance. An insulated counterpoise is connected to the coupling unit and to ground through an inductance which is tuned so as to maximize the field strength radiated in the far field. >

A new and systems oriented method of directional antenna tuning

The AM antenna tuning method presented takes into account and absorbs stray inductances and capacitances, and mutual coupling between components with very high initial adjustment accuracy. Besides an antenna monitor and a field strength meter, the equipment used for tuning consists of a high-precision reflectometer, a spring-loaded and side-handled split toroidal clamp-on ammeter, and a Hewlett-Packard HP-15 programmable calculator programmed with routines used to analyze measured raw data. These programs are written to determine power distribution, transmission line matching conditions and phase shifts. The techniques described inherently minimize the number of different ground points one must refer to. In addition, the few grounds needed with these techniques are much closer to true ground. >