The present invention relates to a log periodic dipole antenna-coupled yagi antenna.

The broadband dipole (2) is attached to the balanced transmission line (6) of the log-periodic array (4) in a manner that continues the inter-element phase reversals characteristic of the log-periodic dipole array.

According to the log periodic dipole antenna-coupled yagi antenna, a log periodic dipole antenna (LPDA) is connected to a wave guide of the yagi antenna to increase gain, thereby resonating into a wide frequency band.

Thus, for example, a log-periodic dipole antenna is not suitable.

A compact broadband log-periodic antenna (5) for transmitting and receiving frequencies between 0.5 to 18 GHz.

A microwave multiplexer includes a first channel segment (8) having first components (Ai, Bi, Ci, Ji) derived from a first log-periodically scaled prototype.

The antenna has a log periodic dipole array (14), a director section (16), and focusing element (18), and where the director section has a plurality of director elements (20).

The log-periodic dipole array system has the advantages that linear phase characteristics can be obtained without sacrificing high radiation efficiency and gain.

A log periodic dipole antenna in which some, or preferably all, of the mechanical attachments do not include metal-to-metal contact points.

In addition, the multiplexer includes a second channel segment (4, 6), connected to the first channel segment (8) and having second components (Ai, Bi, Ci, Ji) derived from a second log-periodically scaled prototype.