DESIGN & CONSTRUCTION OF 100+MHZ FREQUENCY COUNTER

Abstract

A frequency counter is an electronic instrument used to measure the frequency of an input signal, it operates on the principle of the input signal into the counter which assembles the number of event occurring within a specific period of time. The accuracy of the measurement is directly related to the internal resolution of the counter and the accuracy of its internal time base The frequency counter in the project is based on direct counting approach. The power consumption of this counter is very low, it can operate with 12V battery/adapter. The circuit contains only a few components. The brain of this unit is a PIC 16F628A microcontroller which has an instruction clock of up to 4MHz, which1is also the input sampling rate. It has a 16x2 LCD i.e. it can display 32 characters. This counter is capable of measuring frequency up to 1.8 GHz in normal condition with a maximum1amplitude of15V. This project also includes the construction of wave form generator which is AD 9850 (DDS) chip and able to generate signal of up to 50 MHz .