In a mixer used for upconversion, the conversion loss is the difference between the IF input signal’s amplitude and the RF output signal’s amplitude.Ĭonversion loss is expressed as a positive number in decibels. In a mixer used for downconversion, the conversion loss is the difference between the RF input signal’s amplitude and the IF output signal’s amplitude. The specifications, which are described below, help a system designer select an appropriate mixer to meet system requirements.Ĭonversion Loss: In passive mixers, conversion loss is defined as the difference in signal level between the amplitude of the input signal and the amplitude of the desired output signal. These performance metrics are specified in most mixer datasheets. Mixer Performance ParametersĪ mixer’s performance is determined by several metrics.
Upconversion is normally part of a transmitter, while downconversion is typically used in a receiver. Both downconversion and upconversion are shown graphically in Fig. The frequency of this output signal is equal to the sum of the IF input signal’s frequency and the LO signal’s frequency.
These two input signals produce an output signal at the RF port. When a mixer is used to perform upconversion, an input signal enters the IF port and an LO signal enters the LO port. The frequency of this output signal is equal to the difference of the RF input signal’s frequency and the LO signal’s frequency. These two input signals produce an output signal at the IF port. When a mixer is used to perform downconversion, an input signal enters the RF port and an LO signal enters the LO port. The required LO drive level is dependent on several factors, including the mixer’s configuration and device technology. The LO signal is typically the strongest signal injected into a mixer. The RF and IF ports can be used interchangeably, depending on whether the mixer is being used to perform upconversion or downconversion. The three ports of a mixer are known as the intermediate-frequency (IF), radio-frequency (RF), and local-oscillator (LO) ports.