Single-Antenna Receiver Switching for UWB Pulse Protection
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Solution Overview
Problem
The requirement for a high gain amplifier in UWB pulsed radar receivers poses challenges, including the need for high-powered transmitters to generate pulses with sufficient voltage swing for near-range detection, which can damage receiver circuitry. This limits radar architecture design to either two-port full-duplex or single-port half-duplex configurations, restricting near-zero range detection and increasing device size due to the need for separate antennas.
Innovation Solution
A transceiver circuit with a single antenna interface that includes a transmitter and a receiver with two circuit branches: a first branch to connect the receiver input to the output and a second branch to connect the receiver input to a signal ground node. This allows the receiver to divert incoming signals to ground during transmission, protecting sensitive components, and enables pseudo-full-duplex operation by allowing signal leakage during transmit mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high gain amplifier is used in the receiver to amplify weak reflected signals, then the receiver sensitivity is improved, but the transmitter must be high powered which can damage the receiver circuitry
Solution Approach 1:
The patent applies preliminary action by switching the receiver amplifier OFF or blocking it before the high power transmit pulse arrives. The receiver is prepared in advance by disabling the amplifier during transmission, preventing damage before it can occur. This is achieved through timing control where the amplifier is activated only after the transmit pulse has completed.
Solution Approach 2:
The patent implements dynamics by dynamically switching the receiver amplifier between ON and OFF states based on the transmission cycle. The amplifier is OFF during transmission to protect from high power pulses and ON during reception to amplify weak signals. This dynamic state change allows the system to adapt to different operational requirements and avoid damage.
2Reliability
If a two-port full-duplex design is used with separate antennas for transmitter and receiver, then the receiver can be protected from transmit pulses, but the device area increases
Solution Approach 1:
The patent merges the transmitter and receiver into a single-port half-duplex design, combining both functions into one antenna interface. This eliminates the need for separate transmit and receive antennas, reducing the device area significantly. The single antenna serves both transmission and reception functions at different time periods.
Solution Approach 2:
The patent applies universality by making the single antenna serve multiple functions - it acts as both the transmit antenna and the receive antenna. The same physical antenna is used for both transmitting high power pulses and receiving weak reflected signals, eliminating the need for dedicated separate antennas and reducing overall device complexity and area.
3Area of stationary object
If a single-port half-duplex design is used to reduce device area, then the form factor is improved, but near-zero range detection is restricted
Solution Approach 1:
The patent uses periodic action by operating in pulsed mode where the transmitter sends periodic pulses and the receiver periodically switches between transmit and receive modes. This allows the system to detect reflections from very close targets by listening during the intervals between pulses or during the trailing edge of pulses, achieving near-zero range detection capability.
Solution Approach 2:
The patent maintains continuity of useful action by ensuring the receiver is actively listening during the entire transmit pulse duration and immediately afterward. The amplifier remains ON during reception to continuously capture weak reflected signals, including those from very close targets that return during or immediately after transmission, eliminating dead zones.
Data Source
AI summary
A transceiver circuit for transmitting and receiving via a single antenna interface, the transceiver circuit comprising: a transmitter and a receiver, wherein the receiver comprises: a first circuit branch arranged to selectively connect the receiver input to the receiver output; and a second circuit branch arranged to selectively connect the receiver input to a signal ground node. The receiver can be operated to choose which of the two circuit branches to send the signal. In receive mode, the receiver can send the signal over the first circuit branch to the receiver output as normal. In transmit mode, the receiver can send the signal instead over the second circuit branch to ground, thereby dumping the incoming signal, while protecting sensitive processing components downstream of the first circuit branch that are unable to handle the large signal swing of the direct path or reflected transmit pulse.