Here is another DIY antenna, this time for GSM/3G/4G usage. The design was calculated for 800-2100MHz and works well in this range. The antenna has a very broad bandwidth with a low gain and can be used for any application within the frequency range. Since the results are very good even up to 3GHz the antenna is also useful for WiFi. As well as ADS-B (flight radar) because 1090MHz is covered too. In general an excellent antenna for rtl-sdr operations.
Based on this calculator.
Return loss is -10dB or better in the desired operating range 800-2100MHz, VSWR 1.5 or better.
- Disc diameter 90mm
- Disc FR4, single side copper, thickness 0.8mm
- Cone upper diameter 5mm
- Cone lower diameter 115mm
- Cone height 90mm
- Cone angle 60°
- Cone metal sheet thickness 0.3mm
- Spacing cone-disc 2mm (1.2mm nylon nut + 0.8mm FR dielectric)
On the cone template the inner radius is 5mm, outer 114.7mm, torus angle 180°, with overlapping 183°.