Technical Background
The current highway tunnel antennas mainly include log-periodic antennas and panel antennas. Compared with the deployed requirements of operators, there are the below shortcomings of the above-mentioned antennas: Log-periodic antennas only support single polarization, have insufficient capacity, low gain, and close coverage distance, therefore it requires to build many supporting stations, which will high cost of equipment and construction.
Panel antenna has a large size and a larger windward surface, therefore, it is difficult to coordinate in construction during the practical application, and it will bring a sharp rise in volume if further improvement of gain .
Wall-mounted antennas with high bandwidth and high gain are a urgently needed research topic in the industry.
Sigtenna’s technical solutions
Sigtenna’s Tunnel wall-mounted antenna is a new product jointly developed with China Tower for the application in the scenes of highway tunnel. A new broadband dipoles, the invention of Sigtenna, is used in the tunnel wall-mounted antenna to improve the radiation unit gain and expand the bandwidth of the wall-mounted antenna. The width and directivity of the coverage are improved by adding a director at the radiant surface of the high-gain dipole. The gain of the antenna  will be increased by the narrow beam formed by the improved beamwidth again.

Sigtenna’s scheme of Tunnel wall-mounted antenna 

The Sigtenna’s advantages in technology and application 

The antenna adopts the wall-mounted design and compact shape, which can be easily installed on the road and reduce the interference to the road traffic. This antenna with small footprint can adapt to a variety of needs in  environments and installation. Maintenance interface is easy to be used, which is easier to maintain and upgrade. At the same time, the antenna has good compatibility and can be seamlessly connected with other devices and systems to achieve cross-platform and cross-system communication and data transmission. Compared with other antenna technologies, the antenna has lower cost and higher performance, which helps to reduce the construction cost and operation cost, and meet the needs of highway communication. The overall construction cost is 80% lower than that of the leaky cable scheme, and 30% lower than that of the log-periodic antenna scheme, and it is obvious to cut down the investment.

 Index comparison between Sigtenna products and other log-periodic antennas :
Sigtenna index advantages:

1) Gain is increased by 2 to 6dBi, and single sector coverage distance is increased to 1-1.3 km.
2) Support dual-polarization, enhance diversity gain, improve rate and signal stability.

Traditional log-periodic antenna index

Sigtenna’s case in application:
1. Mulzhailing long tunnel should be covered with a total length of 15.2 km. The original plan: the construction involves 128 pairs of log-periodic antennas at 32 points in the coverage of log-periodic antenna, and the workload of equipment installation is large, the risk factor is high, so it is difficult to the coordinate by the highway administration Bureau.
By using Sigtenna’s tunnel wall-mounted antenna,it can reduce the investment by about three-quarters with only 8 points and 32 pairs of tunnel wall-mounted antenna with high gain.