Radio and microwave frequencies all need some sort of control device when you are working with them. You want to be able to make the waves and frequencies do what you want them to do. Otherwise, they just do whatever they ordinarily would do when they are not controlled. To control waves and frequencies, there are two main components used in electronics. They are isolators and circulators. Here is more about what they are, what they do, and what makes them different from each other.
Isolators are electronic components that isolate waves and frequencies. They hold certain waves and frequencies in limbo and separate them from other waves and frequencies that might overlap or overrun the ones you want to control through isolation. These components also prevent specific waves and frequencies from moving forward to mingle with all of the other waves and frequencies ahead of them.
Circulators do something that is somewhat opposite of isolators. These components tend to circulate all waves and frequencies in the same direction without much restriction. As you can imagine, they circulate waves and frequencies together. Circulators do not separate or prevent waves or frequencies from moving, but these components do help direct waves and frequencies in a desired direction.
What Makes Them Different
These components are often referred to as "isolator circulators." It tends to get confusing once you know that these components are two separate types of electronic equipment. However, there are also isolator-circulators, and this third type of device tends to do all of the above, with the added component of a switch that allows users to change the function of the combo component when necessary or desired. When building electronic devices, some companies prefer to use the combo components because it simplifies the use of the electronic device for the consumer. It also makes it easier to repair in the event that the device breaks and needs repair with its isolator-circulator.
What You Need to Know as a Consumer
What you need to know as a consumer is that if you get into building radios of any kind, or fixing TVs and microwaves, you will need to familiarize yourself with these components. There are many different models of isolators and circulators, as well as combo units. It is not a hobby to enter into lightly, so be sure to read lots of books on electronic components before you begin.