Phase Linear Design Technology

Phase Linear Design Technology

In the world of Presentation and Live Events it is necessary to be able to handle a wide range of signal formats and graphics resolutions. These requirements demand that all elements in the system perform such that true signal integrity is maintained from source to display. Simply put, the signal path must be 'clean' from beginning to end in order to guarantee the reproduction of crisp and and artifact-free images.

Clearly the routing switcher is an important element in any Presentation or Live Event system. This places the demand for high-fidelity performance and reliability on the basic design and manufacture of the switcher. There are many factors that affect the performance of a switcher and all of the performance parameters must be given serious consideration in the design of a switcher that must deliver the best possible performance.

The ISIS series of RGBHV routing switchers has been designed to meet the 'image quality' demands of the industry. They are not simply an adaptation of older, composite video designs, built to emulate the RGBHV footprint.

One of the areas of performance that the ISIS engineers considered to be very important was delay inequalities. The result of delay inequalities can be seen as 'ringing or noise' in the image. Digging a little deeper, it can be seen that if the delay lags as frequencies increase, the rising and falling edges of fine lines and other objects in the image will not have symmetrical edges. To complicate matters even further, if the switcher is driving a scaler, any phase errors introduced by the switcher will cause the analog to digital converters in the scaler to produce digital artifacts that will appear as aliasing errors.

It is clear therefore that, if all of the frequency components of the signal arrive at the routing switcher at the same time, they should leave the output of the switcher at the same time. While it may seem logical that this would be the case, in actual practice this can be quite difficult to achieve - thus the reasoning behind the use of phase linear design technology in all ISIS RGBHV routing switchers.

Phase linear technology is not new. However, ISIS has recognized just how important this technology is when passing distortion-free high-resolution signals through a routing switcher. Simply put, the use of phase linear technology ensures that signal delay inequalities within a given signal path are eliminated.

Users of the ISIS RGBHV routing switchers have been very complimentary about the clarity and crispness of images when using the switchers in real-world applications. Various switcher models have been 'stacked' against competitive equipment during live events in Europe and the US. Multiple high-resolution images were used to feed high-end projectors on large screens to produce blended images. The ISIS switchers came out on top. The comments received include cleaner, crisp, more stable images etc. While this may be subjective, it is real world proof that we are doing things right.

*** For more information about the ISIS RGBHV routing switchers click here.