HDTV Antennas

John Ross & Associates, LLC has been working with Antennas Direct since 2006. Over the course of this long and productive relationship we have developed numerous HDTV receiving antennas and accessories. A few of these projects are outlined below.

Clearstream TM Antennas

Our first project with Antennas Direct lead to the development of the ClearstreamTM series of HDTV antennas. These patented antennas are based on a novel tapered loop element that provides enhanced bandwidth and efficiency in a small aesthetically pleasing form factor. A variety of indoor and outdoor models have been developed around single (C1), dual (C2), and quad (C4) UHF tapered loop configurations. There is also an exemplary outdoor high VHF band model known as the C5. The unique figure 8 look of the C2 element has become an industry icon for the HDTV antenna.

We have developed numerous variants of the original antennas for both indoor and outdoor use. Some of the most popular models make use of a reusable sticky pad that make them easy to mount on walls and windows. These antennas make an ideal antenna solution for those living in apartments, dorms or traveling in an RV.

Most newer ClearStream models, such as the ClearStream 4Max below, offer enhanced high VHF band reception through the addition of a dipole and diplexer assembly.

In some cases VHF band reception was realized by the addition of carefully crafted VHF parasitic elements. This approach is more difficult technically but results in a substantial reduction in size and cost by the elimination of the diplexer and related components. One of these elements was integrated into a picture frame. The ClearStream View provides excellent performance with a stealth look that goes nearly unnoticed in most living rooms. The same element geometry was also used in the compact ClearStream Flex indoor antenna as well as the ClearStream FUSION outdoor antenna.

Enhanced Bow-Tie Antennas

In addition to the Clearstream TM line, we also designed a series of enhanced UHF bowtie antennas to replace the popular DB2, DB4 and DB8 line. The new models (DB2e, DB4e and DB8e) have larger elements and reflectors as well as improved feed systems that optimize performance for the post 2009 UHF DTV bands. The new models are specified as UHF only, but the improved feed system makes it more likely that the consumer can benefit from residual reception in the high VHF band. The dielectric tubing at the end of the bowtie elements prevent injury in situations when the antennas are installed indoors or at low elevations. The elements of the DB8e shown below can be rotated to produce beams in different directions to solve tough reception problems.

VHF/UHF Electronics

Our work with Antennas Direct naturally involves passive and active electronics such as amplifiers, diplexers, filters and combiners. We work closely with the Antennas Direct team and various manufacturers in the design, development and testing of such products. We use specialized RF circuit design and full wave EM simulation to optimize performance and speed development time. An annotated top view of a PCB that combines a VHF balun with a VHF/UHF diplexer and UHF splitter as modeled in the Remcom X-FDTD simulator is shown below.

We also carry out the various RF tests on prototype and early production samples to ensure that the devices are meeting design requirements. The tests are carried out in our own laboraotry and include such things as gain, noise figure, S-parameters, P1dB, IMD OIP3, EM Shielding and EMI/RFI, etc.

CEA909A Smart Antenna

In 2008 we partnered with Antennas Direct (through Viamorph, Inc. ) to develop a state-of-the-art CEA909/CEA909A compliant indoor smart antenna for the National Association of Broadcasters. This effort resulted in a reference design for an indoor smart antenna as well as a device that adds smart antenna functionality to traditional fixed geometry antennas. The novel UHF antenna element used a circular disc patch antenna with shorting pins and multiple feeds to effect polarization switching and tuning within the UHF band. The ability to tune the antenna to the proper frequency enabled us to create a much thinner patch antenna than had we been required to cover the entire UHF DTV band instantaneously. The patch antenna ground planes were used as a plate dipole for VHF band reception. Coupled with a compatible receiver containing suitable firmware, the antenna could be configured for optimal signal reception for each channel. The parameters for each channel would be determined during the initial channel scan and stored in memory so that the antenna could hop to the best state for each channel as the user changed channels. With properly impelmented firmware, the antenna could be reconfigured on the fly to restore reception should signal levels drop below a defined threshold.

A photograph of our first prototype mounted in a pair of hinged wooden picture frames is shown below.

Sadly, for reasons well beyond our control, the CEA909 smart antenna standards did not see commercial success in the marketplace. Nevertheless, our smart antenna technology was granted a US utility patent in 2014:

R.E. Schneider, J.E. Ross, D.E. Young, and D.P. Koller, “Smart Antenna Systems Suitable for Reception of Digital Television Signals,” US 8648770, February 11, 2014.

We continue to work with Antennas Direct in the development of new and useful products for the cord cutting consumer.

Antennas Direct products can be purchased at www.antennasdirect.com, Best Buy, Walmart, and Amazon and many retailers.

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Last updated March 10, 2020.