Itâs also essential for keeping your nerves, heart, and muscles functioning properly. Since calcium is so important for many of your bodyâs functions, its levels need to be within a tight range. A second calcium blood test, called the ionized calcium blood test, measures the amount of âfreeâ calcium present in your blood. âFree calciumâ refers to calcium thatâs not bound to any proteins and not together with an anion in your blood.
The hybrid ring coupler, also called the rat-race coupler, is a four-port 3 dB directional coupler consisting of a 3Î»/2 ring of transmission line with four lines at the intervals shown in figure 12. Power input at port 1 splits and travels both ways round the ring.
Power dividers (also power splitters and, when used in reverse, power combiners) and directional couplers are passive devices used in the field of radio technology. They couple a defined amount of the electromagnetic power in a transmission line to a port enabling the signal to be used in another circuit. An essential feature of directional couplers is that they only couple power flowing in one direction.