Pagoda 2 Antenna RHCP (ขั้วเมีย รูเกลียวใน) สายอากาศ FPV 5.8GHz ยอดนิยม ราคาต่อ 1 ชิ้น Pagoda2

Pagoda 2 Antenna RHCP (ขั้ว RPSMA)

สายอากาศ FPV 5.8GHz ยอดนิยม ราคาต่อ 1 ชิ้น

ออกแบบโดย Mr. Marrten Baert

อัตราขยายดี การแผ่กระจายคลื่นยอดเยี่ยม กำลังเป็นที่นิยมในวงการ FPV ต่างประเทศขณะนี้

Specifications

• Center frequency: 5.8 GHz

• Bandwidth: 500 MHz (5.55 – 6.05 GHz)

• Matching: S11 < -20 dB, VSWR < 1.22 (at center frequency)

• Axial ratio: < 1.3

• Radiation efficiency: 95%

Originally the radiation efficiency was listed as 92%, this was a mistake. These values are based on simulation, actual measurements are below (they are very similar). The center frequency may shift a bit between batches as a result of variations in the dielectric constant of FR4. Also, not all brands of FR4 have the same dielectric constant. Frequency shifts up to 100 MHz are normal.

Radiation pattern

For comparison, here's a simulation of the traditional cloverleaf antenna using the same simulation software and setup:

The 'best case' and 'worst case' correspond to different assumptions about what happens to signals that travel along the outside of the coax. In the 'best case' simulation, these are completely absorbed at the other end of the coax. In the 'worst case' simulation, they are completely reflected back towards the antenna. The latter case usually results in standing waves on the outside of the coax, which causes the coax itself to radiate and interfere with the radiation pattern of the antenna. This is why the radiation pattern isn't smooth anymore. The reality will be somewhere between these two extremes.

Measurements