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HOW THE CONTINUUM 2.4GHz TECHNOLOGY PLATFORM WORKS
Microwave energy at a frequency of 2.4 GHz is focused into a small transparent glass ampoule (called a Burner) containing a noble gas at low pressure and microgramme quantities of selected metal halide salts. The microwave energy focused into the waveguide containing the burner forms an electric field ionizing the noble gas molecules to rapidly form a gas plasma within the glass ampoule, the plasma begins to vaporize the metal halide salts present. The plasma and metal halide salts combine to emit light, this technique provides the ability to produce a broad spectral emission using simple chemical compounds. This molecular excitation is a unique feature of the technology and allows us to deliver the world's first mercury-free High Intensity Discharge lamp that can deliver white light of exceptional purity (a Colour Rendering Index (CRI) measurement of 97 being achievable), and which also meets all current and projected regulations for control of radio frequency emission from any part of the system.
The Burner
Figure 1
The burner is made of low hydroxyl quartz glass and contains no metal wires or metal electrodes. This allows the light formation from the plasma process to continue without contamination of the burner contents by metal wires or electrodes modifying the internal chemistry. This simplicity of construction maintains an unprecedented purity of materials within the burner during its continuing operation and allows the lighting platform to offer designers excellent colour constancy and lumen maintenance over an extended operating lifetime.
Figure 2
Figure 3
Figure 1,2,3 Examples of spectrum from various light mixtures.
The Waveguide
Ceravision's original innovation utilises focused microwave energy to excite the burner. The microwave energy produced is fully contained within a dielectric waveguide made from ceramic or similar materials. The waveguide itself is compact and is available in numerous configurations.
The Microwave Interface unit (R-EFF™)
When the lamp is operating the R-EFF microwave interface unit allows microwave energy from the power amplifier to pass into the waveguide and burner assembly, but prevents reflected microwave energy from bouncing back from the waveguide towards the amplifier. This patented component is unique to Ceravision products, and allows high-reliability, long-life systems to be built at low material costs. Using the R-EFF interface unit with the Waveguide and Burner assembly, there is no need for any expensive and complicated electronic circuitry to continually monitor and adjust the RF microwave power source operating characteristics. The R-EFF allows any solid state derived power source to operate in a phase locked spot frequency mode in either a continuous wave or modulated form.
The Microwave Power Source
The Ceravision lighting system can use a wide variety of simple, low-cost microwave power sources. Ceravision currently uses a range of microwave power sources comprises designs with various microwave technologies to deliver power at different levels and costs.
Current designs include:
Gallium Arsenide microwave power transistors between 50W and 400W
Gallium Nitride microwave power transistors between 50W and 400W
LD Mos Silicon microwave power transistors between 50W and 400W
Magnetron microwave power tubes between 100W and 5KW
The choice of microwave power technology is determined by customer requirements in power level, mechanical size constraints, operating lifetime and system cost for their specific application.
 Figure 4. Continuum 2.4GHz System |