In the art of RF antennal technology, cavity resonators are used to generate RF carrier signal(s) that may be combined by an RF combiner assembly and transmitted on one transmit antenna. A drawback of the current technology is that once RF carrier frequencies and bandwidths of a cavity resonator are set and the system put into the field, such as at a public safety transmit site, changes to the bandwidths of the RF carrier signals being presented for transmission to the transmit antenna cannot be readily implemented in the field without first disabling the transmitter. More particularly, in the current state of the art, expanding some RF carrier signal characteristics (such as bandwidth) has to be addressed by adding more site antenna(s) and separate equipment rack(s) to accommodate different carrier bandwidths. This requires taking down the site to make the additions, a solution that is costly in terms of both capital expansion costs and downtime at the site.
For example, a user wishing to offer high speed data (HSD) would have to add a separate, dedicated transmit antenna(s) for HSD, adding significant cost and complexity in site design. HSD has more than a 25 kHz wide composite carrier, and is also referred to herein as “high data speed” or HSD. HSD will allow public safety agencies to communicate at higher data rates.
Thus, there exists a need for an RF cavity resonator and cavity combiner assemblies that permit changes to bandwidth of constituent RF carrier signals while operational and under power and while maintaining desired frequency agility.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of various embodiments. In addition, the description and drawings do not necessarily require the order illustrated. It will be further appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. Apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the various embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Thus, it will be appreciated that for simplicity and clarity of illustration, common and well-understood elements that are useful or necessary in a commercially feasible embodiment may not be depicted in order to facilitate a less obstructed view of these various embodiments.