Abstract: Antennas are a fundamental component of modern communications systems. It forms the interface between the free space and the transmitter or receiver. The transmission line (cable) is terminated by antenna that does not match the characteristic impedance of the transmission line, not all of the power is absorbed by the termination. Part of the power is reflected back to the transmission line. The forward (or incident) signal mixes with the reverse (or reflected) signal to cause a voltage standing wave pattern on the transmission line. The voltage standing wave ratio (VSWR) can also be represented by Return Loss, Mismatch Loss and Reflection Coefficient. This paper represents the details VSWR, impedance and power loss of Log Periodic Dipole Array (LPDA) of frequency range of 160MHz to 1900MHz with 24 elements. Using antenna trainer kit (Transmitter, Receiver) frequency range up to 1300MHz, LPDA impedance variation is about 50 ± 15 O and power loss in % is within 0 to 10 are reported. The VSWR values are within 1 to 2. The results indicate that the constructed LPDA is of good quality to use it for different high frequencies applications.
Keywords: Transmitter, Receiver, LPDA, Impedance matching, VSWR, Power loss.