Minimum envelope roughness pulse design for reduced amplifier distortion in parallel excitation.
Minimum envelope roughness pulse design for reduced amplifier distortion in parallel excitation.
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DOI：
10.1002/mrm.22512
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发表时间：
2010-11
影响因子：
3.3
通讯作者：
Pauly, John M.
中科院分区：
文献类型：
--
作者：
Grissom, William A.;Kerr, Adam B.;Stang, Pascal;Scott, Greig C.;Pauly, John M.
并行激励采用多个传输通道和线圈，每个通道和线圈均由独立波形驱动，为脉冲设计者提供补充梯度编码的额外空间编码机制。与并行接收相比，并行激励需要为每个发射通道配备单独的功率放大器，这可能成本高昂。几个小组已经探索了使用低成本功率放大器进行并行激励，然而，此类放大器通常表现出非线性记忆效应，导致射频脉冲失真。对于具有快速变化包络的脉冲尤其如此，这在并行激励中很常见。为了克服这个问题，我们引入了一种并行激励脉冲设计技术，可以产生具有更平滑包络的脉冲。我们通过实验证明，采用新技术设计的脉冲比未规整脉冲和采用传统正则化设计的脉冲遭受的放大器失真更小。
Parallel excitation employs multiple transmit channels and coils, each driven by independent waveforms, to afford the pulse designer an additional spatial encoding mechanism that complements gradient encoding. In contrast to parallel reception, parallel excitation requires individual power amplifiers for each transmit channel, which can be cost-prohibitive. Several groups have explored the use of low-cost power amplifiers for parallel excitation, however, such amplifiers commonly exhibit nonlinear memory effects that distort RF pulses. This is especially true for pulses with rapidly-varying envelopes, which are common in parallel excitation. To overcome this problem, we introduce a technique for parallel excitation pulse design that yields pulses with smoother envelopes. We demonstrate experimentally that pulses designed with the new technique suffer less amplifier distortion than unregularized pulses and pulses designed with conventional regularization.
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影响因子：
3.3
作者：
SCHNEIDER, E;GLOVER, G
通讯作者：
GLOVER, G
影响因子：
3.3
作者：
Xu, Dan;King, Kevin F.;Liang, Zhi-Pei
通讯作者：
Liang, Zhi-Pei
DOI：
10.1109/tmtt.2005.845723
发表时间：
2005-04-01
影响因子：
4.3
作者：
Pedro, JC;Maas, SA
通讯作者：
Maas, SA
影响因子：
3.3
作者：
Grissom, William;Yip, Chun-yu;Noll, Douglas C.
通讯作者：
Noll, Douglas C.
影响因子：
10.6
作者：
Grissom WA;Xu D;Kerr AB;Fessler JA;Noll DC
通讯作者：
Noll DC