https://forum.microwaves101.com/categories/1/antennas/feed.rss Wed, 17 Jun 2026 01:01:20 Z Antennas - Microwaves 101 Discussion Board en https://forum.microwaves101.com/discussion/223/instability-found-when-cascading-microwave-amplifiers Mon, 02 Sep 2024 19:04:46 Z Norman grody 223@/discussions I have been trying to construct a radiometer at around 2 GHz. This is more difficult than the ones I constructed between 4 and 22 GHz since there are no available LNA’s at high gain (60 dB). As such I was forced to cascade two rf amplifier, each having about 30 dB gain. However, I find that the... https://forum.microwaves101.com/discussion/207/near-field-microwave-measurements Mon, 17 Apr 2023 02:36:37 Z Norman grody 207@/discussions I wonder if anyone has tried measuring the field distribution close to an antenna aperture using probes? Possibly, such near field measurements could then be used to determine the emissivity or reflectivity of materials placed in front of the antenna. In this way one could use near field... https://forum.microwaves101.com/discussion/187/simulation-antenna-set Sun, 03 Apr 2022 09:04:25 Z Pietro 187@/discussions Good morning I would like to place a question. I need to simulate a number of antennas placed on an imported geometry. Probably around 20 antennas. In the end I am interested in the scattering parameters of the structure. The antennas are not meant to be simulated, the radiation data are coming... https://forum.microwaves101.com/discussion/181/anyone-working-in-the-50-70-ghz-range Mon, 14 Mar 2022 16:36:10 Z Admin 181@/discussions We recently got a note from loyal reader Kevin, who says: " I have equipment I am trying to part with that I have no need for. Simply put I have a Sage 50-70GHz microwave to 1.85mm sma feed that needs a good home, and maybe feed horn on it or whatever kind microwave tube you would like to attach."... https://forum.microwaves101.com/discussion/179/monopulse-equations Thu, 11 Nov 2021 23:11:52 Z UnknownEditor 179@/discussions Looking for some simple equations for a monopulse network, to put into Excel to show pre-monopulse phase and amplitude error effects on null depth, etc. Something we could post on this site! Thanks in advance Steve https://forum.microwaves101.com/discussion/162/circular-waveguide-dimention Tue, 09 Mar 2021 09:31:13 Z Thomas 162@/discussions Hi I am looking into using a circular waveguide for a dual polarized feed and have some thoughts of what diameter I should chose for the circular waveguide. An internet search gives tables for *standard* dimensions for circular waveguides. My frequency band is the commercial backhaul E-band, i.e.... https://forum.microwaves101.com/discussion/143/gain-pattern-in-fernfield Mon, 28 Sep 2020 09:04:58 Z Fei 143@/discussions Hello, everyone. How can man change the Gain pattern in Fernfield? for example, PIFA Antenna has often gain pattern upward to sky, I want to change the most Gain pattern to the elevation grad 90°, That means, polarisation from horizontal to vertical, how can man change the PIFA's polarisation? Have... https://forum.microwaves101.com/discussion/127/radiated-emission-from-power-cable Tue, 23 Jun 2020 08:52:53 Z arezoued 127@/discussions Hi, i have radiated emission problem in one of our product. the 3th harmonic of the clock frequency radiate from the power cable. the cable is shielded with foil and braid. when we test it in EMC lab we used 15 meter long power cable, and because it was too long, the lab coiled it (like a loop... https://forum.microwaves101.com/discussion/129/circular-dual-linear-polarized-cantenna Mon, 22 Jun 2020 16:05:12 Z Edyasia 129@/discussions Hi everyone, i need make for 5ghz a/n link a circular dual polarization waveguide. i start building a standard single polarization "cantenna" and i need to know if second probe (90 degree) is placed at same distance from reflector as first probe or twice distance (any formula?). Antenna will be... https://forum.microwaves101.com/discussion/119/maximally-flat-impedance-transformers Sat, 20 Jun 2020 18:30:46 Z Ronan 119@/discussions Greetings! I am hoping someone can point me in the right direction -- I am an amateur radio operator/builder attempting to build and test a dual rhombic antenna, per the author's plan in August 1977 QST article by W8DMR. See figure 4 pg. 26. The antenna was designed for 435-870 MHz, though my... https://forum.microwaves101.com/discussion/75/5g-basics Mon, 08 Jun 2020 20:36:50 Z jay 75@/discussions I googled however if anyone has any customized simple presentation/document that covers 5G basics, frequency band details, antenna design etc.. for the beginners, kindly share. https://forum.microwaves101.com/discussion/122/looking-for-faqs-on-cassegrains Fri, 01 Nov 2019 00:43:04 Z MMwave 122@/discussions I'm populating my page and looking for common FAQs that engineers typically write when looking for cassegrain reflector antennas? From the easy to the complex. Any FAQs would be great as I look to populate the page with solid info. Thanks! https://forum.microwaves101.com/discussion/73/passive-intermodulation Mon, 25 Feb 2019 11:16:43 Z jos 73@/discussions What is/are some good sources for Passive Intermodulation to bridge the gaps in the RF world for better clarity and understanding? Like something with a lot of information, Large book etc? Easy to understand? This regards EMI and IM/PIM integrated Antennas... Thanks, and if the question I am asking... https://forum.microwaves101.com/discussion/15/impedance-of-free-space Wed, 18 Jul 2018 03:48:37 Z Admin 15@/discussions UnknownEditor created the topic: Impedance of free space How would someone measure the impedance of free space experimentally to verify it? Thanks Steve https://forum.microwaves101.com/discussion/14/tuning-u-fl-antenna-cable-assemblies Wed, 18 Jul 2018 03:44:43 Z Admin 14@/discussions fff created the topic: Tuning U.FL / Antenna Cable Assemblies Cellular, Wi-Fi, GNSS and Bluetooth radios are available as FCC-certified modules with a U.FL connector that connect to an external antenna through a cable assembly. Why do you never see an antenna matching network in finished products... https://forum.microwaves101.com/discussion/13/earthing-quality-measurement-with-an-antenna Wed, 18 Jul 2018 03:43:14 Z Admin 13@/discussions metin created the topic: earthing quality measurement with an antenna I wonder if it would be possible to measure the earthing quality with an RF antenna. My idea is to fees some voltage between an antenna and the earth terminal and measure the current. Then I would guess the earthing impedance... https://forum.microwaves101.com/discussion/12/calculate-antenna-gain-from-measured-data Wed, 18 Jul 2018 03:30:32 Z Admin 12@/discussions Ahsan created the topic: Calculate antenna gain from measured data. I have measured antenna data and I want to analyze it using matlab. I have Etheta and Ephi values for a particular frequency. How can I calculate Gain of an antenna with the help of this data. Any ideas ?????? https://forum.microwaves101.com/discussion/11/online-calculator-to-design-circularly-polarized-microstrip-antennas Tue, 17 Jul 2018 05:02:45 Z Admin 11@/discussions dfmona created the topic: Online Calculator to design Circularly Polarized Microstrip Antennas online calculator that designs circularly polarized microstrip antennas with a selectable input impedance. The tool calculates the antenna dimensions and probe position that generate both circular... https://forum.microwaves101.com/discussion/1/hello-and-welcome-to-your-new-forum Sat, 24 Feb 2018 18:21:02 Z Admin 1@/discussions Before you open the doors, don't forget to change your email address and password. Select "You" from the menu at the top, then "Edit Profile". Don't worry, you'll get to update your name in the process. But first, a few words from our founder: Read through our simple Getting Started guide and...