Amateur Radio VHF/UHF CJU Directional Antenna

3-unit CJU directional antenna production. The CJU antenna was originally released by Spanish amateur radio enthusiast EA4CYQ in 2006. The full name of the CJU antenna is CANARY JAIL UMBRELLA. It is a single-band 2-unit directional antenna, while the IOIO antenna is a dual-band version of the CJU antenna. Regarding the origin of the CJU antenna, when EA4CYQ was conceiving a lightweight UHF antenna, his father EA4ABV (also an amateur radio enthusiast) proposed that a plastic tube can be taken out of the canary cage (CANARY JAIL) as an antenna. Main pole, and then EA4CYQ found the steel wire umbrella pole of a broken umbrella (UMBRELLA) in the trash can as the driving unit and reflection unit of the antenna.
After the release of the CJU directional antenna, it was further optimized by Mr. Aiji Nakamura, a Japanese amateur radio enthusiast, JA1CPA, and a 3-unit CJU antenna working in the UHF band was produced. JA1CPA is a persistent antenna enthusiast. Through repeated testing and verification, he has improved CJU antennas with different architectures. The highest gain reaches 9.88dBi. In order to achieve the best match, JA1CPA conducted multiple tests just because of the adjustment of the core wire and braid of the coaxial cable.
Referring to the information of the above two enthusiasts, I also tried to make a CJU directional antenna for UHF amateur band communication.