Linearization Technique of Diplexer-Free Transmitter for Carrier Aggregation Signals

Linearization Technique of Diplexer-Free Transmitter for Carrier Aggregation Signals
January, 11, 2018
1061 | Meyer

Graduate Seminar

Speaker: Nimrod Ginzberg
Affiliation: Electrical Eng., Technion

The growing demand for high data-rates transmission in modern wireless communication systems has motivated the development of broadband wireless technologies to support increased channel capacity with good spectral efficiency. Carrier aggregation (CA) is a configuration in which two or more component carriers are aggregated on the physical layer to support wider transmission bandwidths for higher data throughput. CA is supported by different communication standards, specifying the possible number of aggregated channels and the bandwidth of each channel.
For example, the IEEE 802.11ac standard allows for aggregation of several WLAN very high throughput (VHT) channels of up to 160MHz signal bandwidth over the 5GHz UNII frequency band, and the LTE-Advanced standard supports aggregation of five channels, 20MHz each, to achieve total aggregated channel bandwidth of 100MHz in 4G cellular communication.
We propose a linearization technique for out-of-band third-order intermodulation distortion (IMD3) of widely spaced intra-band CA signals. The proposed technique is based on low power and narrow-band inband signal injection, and implemented in a two-tone post-combining transmitter, consisting of two power amplifiers (PA) connected in parallel to a single antenna. Efficiency degradation due to mutual PA loading is addressed by designing the PAs to introduce high output impedance. The high output impedance characteristic, together with IMD3 compensation, enable diplexerfree transmission within a single antenna of two carriers along the aggregated transmission band.

*MSc student under the supervision of Prof. Emanuel Cohen