US 12,763,921 B2 · Radio frequency front end for FDD-TDD carrier aggregation systems and methods

Abstract

Radio-frequency front end circuitry systems and methods for carrier aggregation include multiple RF signal paths, switching circuitry, and timing control circuitry. The switching circuitry is configured to selectively couple the RF signal paths to an antenna port and includes, for each RF signal path, a thru switch connecting a corresponding RF signal path to the antenna port when activated, and a shunt switch connected between its corresponding signal path and RF ground. The timing control circuitry for each TDD path may include a thru control signal path connecting a control signal to the thru switch and a shunt control signal path with at least one delay element to delay the shunt control signal. The timing control circuitry may include delay elements, a resistor-capacitor circuit and a Schmitt trigger. The timing control circuitry may include a non-overlap circuit for each TDD path to mitigate overlap in switching operations.

Claims20

Dependent claims

A circuit comprising:

a plurality of RF signal paths;
switching circuitry configured to selectively couple the plurality of RF signal paths to an antenna port, the switching circuitry comprising, for each of the plurality of RF signal paths:
a thru switch configured to selectively couple a corresponding one of the plurality of RF signal paths to the antenna port when enabled;
and
a shunt switch connected to the corresponding one of the plurality of RF signal paths, the shunt switch configured to isolate the corresponding RF signal path when the thru switch is disabled;
and
timing control circuitry configured to sequentially activate the shunt switch on a disabled RF signal path and the thru switch on an enabled RF signal path, the timing control circuitry comprising:
a shunt control signal path comprising at least one delay element to delay a shunt control signal;
a resistor-capacitor circuit configured to receive the delayed shunt control signal from the at least one delay element;
and
a Schmitt trigger connected in series with the resistor-capacitor circuit and configured to condition the delayed shunt control signal for output to the shunt switch.

8 more elements

A circuit comprising:

a first RF signal path comprising a first RF filter;
a second RF signal path comprising a second RF filter;
and
a plurality of switches configured to alternately couple one of the first RF signal path and the second RF signal path to an antenna port, the plurality of switches comprising:
a first thru switch configured to selectively couple the first RF signal path to the antenna port when enabled;
a first shunt switch connected to the first RF signal path, the first shunt switch configured to isolate the first signal path when the first thru switch is disabled;
a second thru switch configured to selectively couple the second RF signal path to the antenna port when enabled;
a second shunt switch connected to the second RF signal path, the second shunt switch configured to isolate the second signal path when the first thru switch is disabled;
and
control circuitry configured to control signal timing to the first shunt switch, first thru switch, second shunt switch, and second thru switch, to avoid simultaneous activation of the first RF filter and the second RF filter, the control circuitry comprising:
a shunt control signal path comprising at least one delay element to delay a shunt control signal;
a resistor-capacitor circuit configured to receive the delayed shunt control signal from the at least one delay element;
and
a Schmitt trigger connected in series with the resistor-capacitor circuit and configured to condition the delayed shunt control signal for output to the first shunt switch or the second shunt switch.

11 more elements

A method of operating a radio frequency (RF) circuit comprising a plurality of RF signal paths switchably coupled to an antenna port, the RF signal paths including a first RF signal path and a second RF signal path, the method comprising:

facilitating RF communications on the first RF signal path by:
coupling the first RF signal path to the antenna port by enabling a thru switch of the first RF signal path and disabling a shunt switch of the first RF signal path;
and
decoupling the second RF signal path from the antenna port by disabling a thru switch of the second RF signal path and enabling a shunt switch of the second RF signal path;
and
switching RF communications to the second RF signal path by providing control signals to disable the thru switch of the first RF signal path, disable the shunt switch of the second RF signal path, enable the shunt switch of the first RF signal path, and enable the thru switch of the second RF signal path;
sending the control signals through timing control circuitry comprising:
a resistor-capacitor circuit configured to receive a delayed shunt control signal from at least one delay element;
and
a Schmitt trigger connected in series with the resistor-capacitor circuit and configured to condition the delayed shunt control signal for output to the shunt switch;
and
wherein the control signals are timed to avoid simultaneous activation of the first RF signal path and the second RF signal path without interruption of RF communications via the antenna port.

9 more elements

Dependencies are inferred from the claim text.

Radio frequency front end for FDD-TDD carrier aggregation systems and methods

Life of this patent

Radio frequency front end for FDD-TDD carrier aggregation systems and methods

Life of this patent

Abstract

Claims20