Directional coupler design this, my fifth post for my automatic antenna tuner, deals with the design of the directional coupler. This design won the best innovation design competition of the 2012 group iv photonics conference, sponsored by photon design. Since the coupler is a lossless passive element, the sum of the signals power. These products are used in military, medical, automotive, and handset applications around the world 1. Power in each waveguide core of the codirectional waveguide coupler. Both the conductor strips have the width w, the height tand the length l. As an analysis of a threesection coupler given c 1 c 3, c 2 values we can calculate the coupling coefficient of the whole coupler as following. The coupled port on a microstrip, or stripline directional coupler, is closest to the input port because it is a backward wave coupler. Directional coupler design software atlanta rf software continues to expand our product family of rfmicrowave computeraided engineering cae design software for popular directional couplers, with special emphasis on electrical synthesis, dimensional synthesis and frequency analysis. Directional couplers swr detectors for 145mhz 435mhz. Directional coupler calculator converters and calculators. The 87300c coaxial directional coupler, 1 ghz to 26. This design won the best innovation design competition of the 2012 group.
Directivity affects swr accuracy poor directivity means that forward power is getting into the reflected power port and corrupting the reading. This unit can be used as power meter and swr meter for 28mhz to 435mhz. The following figure shows the image of a directional coupler. Zeqin lu, han yun, yun wang, zhitian chen, fan zhang, nicolas a. Especially when high power levels are involved, a properly designed directional. Generally, in design of directional couplers microstrip and stripline forms are used. The housing is a very small teko box, seen onto the bottom. Mcli couplers are offered in both directional and dual directional with many low frequency and high power solutions utilizing both stripline and lumped element technology. This, my fifth post for my automatic antenna tuner, deals with the design of the directional coupler. Transformerbased, ltcc, striplinemicrostrip, bridge, and mmic. Grating assisted directional coupler model photon design. It offers a high flexibility in waveguide design and postprocessing of any output data. A directional couplers parameters can be simulated using a computeraided engineering cae software program such as the advanced design system ads from agilent technologies. Design of strip line directional coupler 30db in ads.
But, how do we design a coupledline coupler with a specific coupling coefficient c. Directional couplers are used to isolate, separate, and combine signals in measurement applications. Although microstrip transmission lines do not support tem and named as quasitem, usually they are assumed to operate in tem mode. Transformerbased, ltcc, striplinemicrostrip, bridge, and mmic designs. There are some directional couplers which enable dc current to pass through. By placing a directional coupler between your rf amplifier and antennaprobe you can use an rf power. Directional coupler useful tools basically directional coupler is a 4 ports device port1 input, port2 transmitted, port3 coupled, port4 isolated, which has many uses in hf technik forward and. Design, simulation and development of wideband directional. We propose here the design, implementation and testing of a compact directional coupler designed for application in nonstandard coaxial line of several kilowatts at the ism frequency of 2. Directional couplers are invaluable components for measuring the power levels of signals in microwave systems. This is a bit way o for which we tried to design it for.
This one engineer set about devising a design for a 6 db coupling. Following equation or formula is used for directional coupler calculator. Microwave engineering directional couplers tutorialspoint. Especially when high power levels are involved, a properly designed directional coupler provides a lowerpower coupled signal that is within the power measurement range of a power meter or spectrum analyzer. Figure 2 this was the design for a tightlycoupled directional coupler. View details 87300d coaxial directional coupler, 6 to 26. The general concepts about multisection directional coupler, and also for our focus threesection are mentioned in the previous design part. Nov, 2015 advanced design system ile yonlu kuplor tasar. Directional coupler is used to couple the microwave power which may be unidirectional or bi directional. Grating assisted directional coupler model simulation. Rigorous approach for design of differential coupledline. The forward travelling wave goes into port 1 and exit from port 2. Directional couplers werlatone rf directional couplers include dual, bi, and uni directional designs with coupling factors from 6 to 70 db coupling.
Bethehole is a waveguide directional coupler, using a single hole, and it works over a narrow band. Theoretical background figure 1 schematic diagram of directional coupler 9. This design won the best innovation design competition of the 2012 group iv. Our directional couplers using low temperature cofired ceramics ltcc are available in a wide range of products with variations in frequency. The model for the coupler is a pair of coupled transmission lines where the distributed self and. By using multisection coupler, the performance of the coupler can be improved. The origin of the name comes from a paper published by h a bethe, titled theory of diffraction by small holes, published. Beamlab is an awardwinning set of simulation tools for beam propagation through optical devices and waveguides. Apr 26, 2016 where v is a phase velocity calculated as cthe free space speed of light. Strategies for planar directional couplers, part 1. Beamlab is an awardwinning set of simulation tools for beam propagation through optical devices and waveguides in your familiar matlab environment. Atlanta rf software continues to expand our product family of rfmicrowave computeraided engineering cae design software for popular directional. The bethehole is a reverse coupler, as opposed to most waveguide couplers that use multihole and are forward couplers.
Directional couplers werlatone rf directional couplers include dual, bi, and unidirectional designs with coupling factors from 6 to 70 db coupling. Directional, bi directional, dual directional and rf taps. Atlanta rf software continues to expand our product family of rfmicrowave computeraided engineering cae design software for popular directional couplers, with special emphasis on electrical synthesis, dimensional synthesis and frequency analysis. Anaren avx corporation cinch connectivity solutions midwest microwave hirose. Notice the input port and the output port on the upper line and the forward port and the reflected port on the bottom line.
Signal power reflection is prevented because the coupling ports signals are isolated from the line output port. It is one of the worlds leading innovators in high performance analog and mixed signal semiconductors and offers a wide variety of products. Your design of directional couplers is well enhanced using our rfmicrowave cae software for the most popular designs needed in your rf circuits. If the input is port 1, then the through port is port 2, the coupled port is port 3, and the isolation port is port 4. Rf couplers directional, bidirectional, dualdirectional. Directional couplers also have a bandwidth in which they operate, and there are design tradeoffs among the mentioned parameters, so the best coupler design ultimately depends upon the application. In this video i will tell you about how to design of strip line directional coupler 30db in ads keysight. The basic function of a directional coupler is to operate on an input so that two output signals are available. Power dividers also power splitters and, when used in reverse, power combiners and directional couplers are passive devices used mostly in the field of radio. Microwave components 8 microwave components chip multilayer hybrid couplers directional coupler ldc15 series 1. By placing a directional coupler between your rf amplifier and antennaprobe you can use an rf power sesnor to monitor the amount of power throughput and verify the measurements from your current monitorsensing probe and spectrum analyzer are accurate. The directional coupler design is classic and well known. Design directional couplers for highpower applications. With 50 years in the rfmicrowave component industry, onsite computerassisted design and rapid prototyping, inhouse milling and turning capabilities and an iso 9001.
Aug 18, 2010 a directional coupler s parameters can be simulated using a computeraided engineering cae software program such as the advanced design system ads from agilent technologies. Directional coupler useful tools basically directional coupler is a 4 ports device port1 input, port2 transmitted, port3 coupled, port4 isolated, which has many uses in hf technik forward and reflected power measurement, automatic level control, etc. The goal was to make much tighter directional couplers. Directional couplers are fourport circuits where one port is isolated from the input port. A small printed circuit board was designed to offer adequate. All directional couplers have, at a minimum, an input, output, and coupling port. Seems like coupling between the lines is a bit too weak. This design uses two times an adc204 or an adc104 from mini circuits. The hairpin filter was designed and simulated using agilent ads 1. Directivity is the measure of ratio of power at the coupled port to the isolated port. Directional, bidirectional, dualdirectional and rf taps. A directional coupler has functions to pick up a part of the output in order to constantly maintain and control the output gain of the power amplifier pa, and to provide feedback to the pa input.
Apr 20, 2020 the goal was to make much tighter directional couplers. Directional couplers werlatone rf directional couplers. Pdf compact directional coupler for power microwave use. Another important directional coupler parameter is directivity. Its construction and testing will follow in a later blog post. However, when the input is applied to the opposite port of an internally terminated coupler. The model for the coupler is a pair of coupled transmission lines where the distributed self and mutual inductances have been replaced by a transformer and the distributed capacitances have been replaced by lumped capacitors. However, when the input is applied to the opposite port of an internally terminated coupler, only one output signal is produced. Optical simulation of a directional coupler beamlab. Here, directivity is defined as the coupling from the outtoref ports minus the coupling from intoref ports. The directional coupler is fabricated by using fr4 substrate.
The coupledline couplerif our design rules are followedresults in an ideal directional coupler. How to specify the best directional coupler for your. Since the coupler is a lossless passive element, the sum of the signals power at ports 1 and 2 equals to the input signal power. Keysight directional coupler and bridge provide superior rf performance in coupling and directivity for power monitoring, source leveling, swept transmission and reflection measurements. Jaeger, and lukas chrostowski, broadband silicon photonic directional coupler using asymmetricwaveguide based phase control. As an analysis of a threesection coupler given c 1 c 3, c 2. The design, fabrication and measurement of microstrip.
And the previous post in this series can be found here. Instead of the coupled signal being 20 db down from the main line signal, the goal was 6 db. Gratingassisted colourless directional coupler simulation with omnisims fefd and fdtd engines and fimmprop software. Introduction it is a four port passive device 9 used in the field of radio technology. Broadband rf directional couplers are a common component in radiated immunity test systems. The reverse travelling wave goes into port 2 and out of port 1. In this paper, the design of three section microstrip directional coupler is presented. Product index rfif and rfid rf directional coupler. Diy dual directional coupler an addon to our scalar.
Directional coupler is a 4port waveguide junction consisting of a primary main waveguide and a secondary auxiliary waveguide. Couplers are passive microwave components used for distributing or combining microwave signals. With a simulation program such as ads, a designer must set up variable parameters that can be used to optimize the directional coupler. Index terms coupling, directivity, isolation, insertion loss, ads software. Oct 12, 2006 directional couplers are invaluable components for measuring the power levels of signals in microwave systems. Gratingassisted colourless directional coupler software simulation using omnisims fefd and fdtd engines and fimmprop. Osa broadband silicon photonic directional coupler using.
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