Although a resonant antenna has a purely resistive feed-point impedance at a particular frequency, many (if not most) applications require using an antenna over a range of frequencies. An antenna's bandwidth specifies the range of frequencies over which its performance does not suffer due to a poor impedance match. Also in the case of a Yagi-Uda array, the use of the antenna very far away from its design frequency reduces the antenna's directivity, thus reducing the usable bandwidth regardless of impedance matching.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What is lessened by the Yagi-Uda design?
Ah, so.. directivity

In 2004 he was admitted as knight of the Légion d'honneur by president Jacques Chirac. On July 15, 2006, Spielberg was also awarded the Gold Hugo Lifetime Achievement Award at the Summer Gala of the Chicago International Film Festival, and also was awarded a Kennedy Center honour on December 3. The tribute to Spielberg featured a short, filmed biography narrated by Tom Hanks and included thank-yous from World War II veterans for Saving Private Ryan, as well as a performance of the finale to Leonard Bernstein's Candide, conducted by John Williams (Spielberg's frequent composer).[citation needed]
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): In what year did Jacques Chirac become president?
Ah, so.. unanswerable

According to the International Energy Agency, cellulosic ethanol biorefineries could allow biofuels to play a much bigger role in the future than organizations such as the IEA previously thought. Cellulosic ethanol can be made from plant matter composed primarily of inedible cellulose fibers that form the stems and branches of most plants. Crop residues (such as corn stalks, wheat straw and rice straw), wood waste, and municipal solid waste are potential sources of cellulosic biomass. Dedicated energy crops, such as switchgrass, are also promising cellulose sources that can be sustainably produced in many regions.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What is a promising cellulose source that can be sustainably produced in many regions?
Ah, so..
Dedicated energy crops