Bi-phase Modulator Driver Using Prescaler Offset for 12 GHz Signals
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Solution Overview
Problem
Conventional bi-phase modulator driver designs are limited in producing high signal swings and non-return-to-zero baseband signals, and they decay unless continually modulated at sufficient rates, which restricts modulation rates and flexibility in phase modulation applications.
Innovation Solution
A bi-phase modulator driver utilizing a prescaler with floating power supplies and offset output to generate a baseband signal with voltage swings centered around zero volts, enabling non-return-to-zero signals and modulation rates up to 12 GHz, by using a prescaler to produce the baseband signal for driving the mixer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional driver designs with amplifiers, switches, and transistors are used, then the device can provide a baseband signal with frequency of 50 MHz to 100 MHz and swing of 600 mV to 800 mV, but the signal swing is limited and the modulation rate is restricted
Solution Approach 1:
The patent changes the fundamental operating parameters of the driver circuit by using a prescaler designed for higher frequency operation (up to 12 GHz) with different voltage swing characteristics. The prescaler operates with a voltage swing of approximately 1.8 volts peak-to-peak, significantly higher than conventional drivers, enabling both increased signal swing and higher modulation rates simultaneously.
2Ease of manufacture
If AC coupled modulator driver designs are used, then the circuit can be implemented with conventional components, but the output signal decays unless continually modulated at sufficient rates
Solution Approach 1:
The patent implements DC coupling between the prescaler and mixer stages, eliminating the need for AC coupling capacitors. This continuous DC connection maintains the baseband signal without decay, allowing the output to remain stable even during non-modulation phases. The prescaler's output is directly connected to the mixer input, ensuring continuous signal presence without requiring continual modulation to prevent decay.
3Ease of operation
If conventional drivers are used that return to zero between bits, then the neutral rest condition is achieved, but additional hardware is needed during non-modulation phases
Solution Approach 1:
The patent inverts the conventional approach by using a non-return-to-zero signaling scheme. Instead of returning to a neutral zero state between bits, the prescaler maintains a continuous voltage level that represents the data state. The floating power supply configuration allows the output to float at appropriate voltage levels without requiring active return-to-zero circuitry, eliminating the need for additional hardware during non-modulation phases.
Data Source
AI summary
A bi-phase modulator including a driver and a mixer. The driver includes a prescaler having an input for receiving a signal and an output for outputting a baseband signal. The mixer includes a mixer having an input coupled to the output of the prescaler for receiving the baseband signal output by the prescaler. The baseband signal output by the prescaler drives the mixer so as to output a modulated waveform from an output of the mixer.