"This paper introduces the FLOSS Free Libre Open Source Software [VEMSA3D], a contraction of "Visual Electromagnetic Simulator for 3D Antennas", which are geometrically modeled, either exactly or approximately, as thin wire polygonal structures; presents its GUI Graphical User Interface capabilities, in interactive mode and/or in handling suitable formed antenna data files; demonstrates the effectiveness of its use in a number of practical antenna applications, with direct comparison to experimental measurements and other freeware results; and provides the inexperienced user with a specific list of instructions to successfully build the given source code by using only freely available IDE Integrated Development Environment tools-including a cross-platform one.…"

"Applying a sparse constraint on the beam pattern has been suggested to suppress the sidelobe of the minimum variance distortionless response (MVDR) beamformer recently. To further improve the performance, we add an improved block-sparse constraint on the beam pattern. It matches the beam pattern better and encourages dense distribution in mainlobe and sparse distribution in sidelobe. The obtained beamformer has a lower sidelobe level and deeper nulls for interference avoidance than the standard sparse constraint based beamformer. Simulation demonstrates that the SINR gain is considerable for its lower sidelobe level and deeper nulling for interference, while the robustness against the mismatch between the steering angle and the direction of arrival (DOA) of the desired signal, caused by imperfect estimation of DOA, is maintained too."

"… Under such QoS constraints and limitations on the interference caused to the primary users, the maximum throughput is identified by finding the effective capacity of the cognitive radio channel. Optimal power allocation strategies are obtained and the optimal channel selection criterion is identified. The intricate interplay between effective capacity, interference and QoS constraints, channel sensing parameters and reliability, fading, and the number of available frequency bands is investigated through numerical results."

"cocoaNEC 2.0 is a Mac OS X application intended primarily for the design and modeling of antennas.

cocoaNEC 2.0 is a Universal Binary Cocoa based application. It runs natively on both Intel based and PowerPC based Macintosh computers that use Mac OS X 10.4 (Tiger) or newer.

The application is free and it can be downloaded from the Download tab button at the top of this page.

Online tutorials, reference manuals and example files for the application are available through the User's Manual tab button. The What's New page lists features that have changed since the previously released version of cocoaNEC 2.0. "

Dammit, why did these not exist when I was a kid and my Dad was trying to teach me this stuff??

"To use the satellite, pirates typically take an ordinary ham radio transmitter, which operates in the 144- to 148-MHZ range, and add a frequency doubler cobbled from coils and a varactor diode. That lets the radio stretch into the lower end of FLTSATCOM's 292- to 317-MHz uplink range. All the gear can be bought near any truck stop for less than $500. Ads on specialized websites offer to perform the conversion for less than $100. Taught the ropes, even rough electricians can make Bolinha-ware.
"I saw it more than once in truck repair shops," says amateur radio operator Adinei Brochi (PY2ADN) "Nearly illiterate men rigged a radio in less than one minute, rolling wire on a coil.""

"According to Mental Floss Magazine, Kennedy managed to work all of the Ku Klux Klan's most secret recruiting and organizational practices into his 1940s radio serial, "Clan Of The Fiery Cross." And as a result, the Man Of Steel dealt a crushing blow to the racist organization:"

"Antenna arrays have been studied and used for years, but the latest NIST work provides several new twists. Unlike the typical case in which antenna arrays boost signals to or from a distant target, a first responder’s radio would be relatively close to the portable transmitters, ideally within the perimeter of the array. More importantly, since disaster sites rarely allow for niceties of design, NIST studied the benefits of a fast and imprecise technique—randomly placed antennas combined with coarse signal matching. The signals produced by the radio and portable transmitters need to operate at the same frequency and roughly in phase, such that the radio waves are fairly well synchronized and thus build on each other. Phase-matching was performed manually in the experiments but might eventually be possible remotely."