|
|
|
Yagis run out of gas at around 10% bandwidth. Logs can be built that cover 1000% bandwidth (100 to 1000 MHz). Log periodics can be stacked for more gain and narrower beamwidth. They can be designed for circular polarity and to "reuse" elements over higher octaves by tilting the elements forward. |
|
CHARACTERISTICS
|
|
Almost unlimited bandwidth possible with 10 to 1 bandwidth quite practical |
|
All elements are driven and when matched to 50 Ohms, 2:1 VSWR peaks are typical |
|
Gain is typically lower than other antenna types; range 3 dBi to 12 dBi |
|
Linear polarity is typical but can be designed to produce circular polarity, either Right Hand or Left Hand |
|
Log periodics can be stacked in arrays for more gain but broadband matching is difficult |
|
|
|
LOG PERIODIC FREQUENCY RANGE
|
|
| HF |
3-30 MHz |
| VHF |
30-300 MHz, 30-100 MHz are typical |
| UHF |
300-1000 MHz and 500-2000 MHz are typical |
|
|
| Of course any combination of HF, VHF, and UHF/micorwave is possible |
|
